Sort by
Relevancy

Free Stories

100%
Reshooting the Scene, Chapter 1
I have been a porn aficionado since I was a teenager. My first dabblings were with Hustler magazine and a *very* hardcore mini-novel called “Her Busted Asshole,” which told the raunchy story of Ginny Cummings’ sexual coming of age. In addition to the very graphic story, it had full color glossy p... Read full Story
Lovelace 2021-06-07 4,527 Bareback threesome Blowjob blonde Big Cock Sex Toys Ass to Mouth
100%
My new Life with Pat. Part 2
While Jean was discussing with the lady from the next table i feel the didlo starting to vibrate and then something like a small ball move up and down into the didlo, it was a prostate massage. I saw Jean playing with a remote control, He increased and deacresed the frequency of vibration and the ... Read full Story
jperrot 2022-08-09 4,943 Amateur Bareback Shemale Fucks Guy threesome Shemale and Girl domination Guy Fucks Shemale slave Ass to Mouth double anal webcams punishment
100%
Big Dick Alessia Visits Dallas
Alessia Hung Mature MILF travels to visit a Big Dicked Man and his Sexy Household If you like Transexuals, big cocks, bondage, BBWs, big clits, deep throat, fisting, 69, ass fucking, sounding, piercing, cum swallowing and big loads this story is for you. If not don't bother reading. If you fav... Read full Story
darrell 2022-04-20 4,342 Group Sex Cumshot Shemale Fucks Guy Blowjob blonde Big Cock Asian Shemale and Girl Sex Toys Mature Ass to Mouth shemale + shemale
85%
My Awkward Phase
My Awkward Phase ©Alexandra Rios 2019 The greatest lie is that what happens in high school doesn't matter, because life begins in college. I pretended to agree, although I never believed it, for I was the world's greatest liar. Wannabees I was hanging out with my friends Quinn, Barb and Anne ... Read full Story
the greatest liar 2019-06-14 11,857 Small Tits anal sex Latina Masturbation Bareback Creampie Blowjob Big Cock transformation gangbang Shemale and Girl Guy Fucks Shemale Sex Toys Ass to Mouth cosplay hormones high school real life situations
100%
The Big Mature Shemale Next Door
The Big Mature Shemale Next Door SugarandSalt "Please can I just wear my old swimming trunks?" Warren begged. "No!" his mom yelled back from the other room. "Barbara purchased that for you. It was expensive so you better remember to thank her." Warren looked at himself in the full length mir... Read full Story
Gwapo67 2022-05-03 7,941 Bareback Creampie Shemale Fucks Guy Blowjob Big Cock Mature cum in mouth
100%
Alessia Travestita Hung Mature Blonde British Porn Star
Alessia Travestita Hung Mature Blonde British Porn Star If you like Transexuals, big cocks, bondage, domination, deep throat, fisting, spit roast, 69, ass fucking, cum swallowing and big loads this story is for you. If not don’t bother reading. If you like my story please leave comments and ... Read full Story
darrell 2022-01-03 4,643 Group Sex Cumshot Bareback Shemale Fucks Guy Blowjob Big Cock gangbang domination Sex Toys Mature cum in mouth shemale + shemale
100%
New Orleans TS dream come true..
In was on New Orleans running water for the victims of Katrina in 2005. I went down to Bourbon St several times an one night I walked into adult fetish store and as I was looking around there was what appeared to be a very beautiful black woman bending over with a very short skirt on. I was admirin... Read full Story
jim3801 2018-09-11 10,636 Group Sex Bareback Shemale Fucks Guy threesome Big Cock Ebony Guy Fucks Shemale Interracial Ass to Mouth cum in mouth
84%
Becoming Zoe
My soon to be wife Annie had taken a job out of town and I only saw her every two weeks or so. I was so missing her. She and I had become long distance lovers. She was scheduled for a flight home on Friday night. I was going to pick up her son Zakk from his dorm and the two of us were going to p... Read full Story
Zöe from Kingston 2018-08-09 9,193 Stockings Teen (18+) Crossdresser Cumshot Bareback Blowjob blonde Big Cock Lingerie Mature cum in mouth
100%
Sissy Slut Reunion
Rob had moved back to town and called me. He had just moved into his new place and he wanted me to come by and talk. I knew what he really wanted from the tone of his voice, because I wanted it too. He said he had been thinking and dreamed about me the whole time he was away. My spirits lifted and ... Read full Story
Regina10 2020-09-14 4,174 Crossdresser Big Tits Cumshot Bareback Creampie Fetish Big Cock Ebony Ladyboy Guy Fucks Shemale Ass to Mouth cum in mouth
80%
How it started
What got me started off watching shemale porn was actually meeting a very beautiful shemale at a beach party. I already knew she was a guy but she was so beautiful. So at one point I asked her if she wanted to go for a walk and after a few minutes and let her know that I was down. Her response was ... Read full Story
PNPFUCKBOY 2019-02-12 11,871 Teen (18+) Small Tits Crossdresser Amateur Big Tits Outdoor Latina Bareback blonde Big Cock Ladyboy domination Guy Fucks Shemale Interracial Sex Toys Mature Homemade Ass to Mouth
40%
Dating all whole my life
Julia and Ilya, together 10 years It was more than 10 years and 2 children ago. In December 2005, we agreed to meet at the gate of my office after a working day. I did not go out godlessly for a long time (40 minutes from the appointed time), but he still waited. I hope he does not regret it ... Read full Story
PornoDating 2019-08-15 3,973 Crossdresser Amateur Big Tits Cumshot Bareback Creampie Fetish Blowjob blonde Big Cock Asian gangbang domination Guy Fucks Shemale Interracial sex Mature Futanari Frottage Compilation Ass to Mouth Cartoon cum in mouth double anal dating life in Mars? life
100%
The four of us
Jan and I have been together now about 4 years but known each other since High School. We are both in our early fifties. We had met a transgendered girl (Gabby) about a year ago and we get together about once a month and enjoy each other’s company, going out playing and having intimacy together. Gab... Read full Story
Jon Paul 2021-08-02 4,197 Group Sex Big Tits Cumshot Bareback Creampie Blowjob Big Cock Guy Fucks Shemale Ass to Mouth
92%
Southern Hospitality Ch. 04
XtinaSmith2017 Ash awoke feeling cold, he pursed his lips a little and shivered, curling up a little tighter, nude as he was, the action brought little relief from the cool air. He let out a soft murr of discomfort as his mind shook off the cobwebs of lingering dreams, he could see light throug... Read full Story
Gwapo67 2022-05-16 6,730 Big Tits Bareback Creampie Shemale Fucks Guy Blowjob Mature cum in mouth
33%
Superstar fun - an evening to remember!
Starting with a little history, let me say that I started getting into tranny fun back around 1990. I went on a visit to New York and had always been an avid reader of Screw magazine/ newspaper. Before the Internet was in full-bloom it was distributed nationally to all cities around the country and ... Read full Story
shemale lover 2012-04-03 3,042 anal sex cum ass licking oral sex 69 position
100%
Florida TG Experience
I had known Jan from High School, we always had an attraction for each other but were dating someone else or married at the time. Jan had actually married a friend of mine and I was envious of course. She at that time had sandy blonde hair, and a body to die for. One evening we had them over for dr... Read full Story
Jon Paul 2018-08-13 10,962 Group Sex Big Tits Bareback Creampie Blowjob blonde Asian Ladyboy Shemale and Girl Guy Fucks Shemale Ass to Mouth cum in mouth double anal
100%
The Experience of a Lifetime
My divorce was hitting me really hard. My wife outgrew our relationship and started living her own life and I had a front row seat to everything. My heart and life was upside down. I didn’t go out anymore. Friends and family both told me it was time to get my life back on track and start living ... Read full Story
therefill05 2020-11-30 20,086 Big Tits Cumshot Bareback Creampie Shemale Fucks Guy threesome Blowjob blonde Big Cock Ebony Uniform domination cum in mouth
88%
My wonderful life with Pat : Domi and Morgan
second part of the tattoo ..... I was nervous to be tied and at her mercy.Morgan put on a mask to make me blind and she tightened the ties to keep me from moving. Then with a very soft voice Morgan sussed me, don’t be afraid, i will make this day an unforgettable one. You will have a such intens... Read full Story
jperrot 2021-04-09 3,171 Amateur Outdoor Masturbation Bareback Shemale Fucks Guy threesome Blowjob domination Ass to Mouth cum in mouth
100%
College project surprise
So this story happened while I was still in college and remains without doubt, the craziest, most exciting experience of my life. So I the story begins one day when I walking to class. I went to a big university so my walk was quite long, and the first 1/3 was just through off our campus housin... Read full Story
Jsmithsub 2020-09-16 21,022 Group Sex Bareback Shemale Fucks Guy Fetish threesome Big Cock Ebony domination Ass to Mouth cum in mouth
87%
Southern Hospitality Ch. 03
XtinaSmith2017 Ash looked himself over in his bedroom mirror critically, finding himself oddly self-conscious about his looks. He had been texting Laura all throughout the day and they had agreed that dressing pretty casual would draw the least suspicion, so he had. He wore a simple patterned ... Read full Story
Gwapo67 2022-05-16 4,777 Bareback Creampie Shemale Fucks Guy Blowjob Big Cock Mature cum in mouth
100%
A Perfect Pandemic: A Transsexual Transition in a Troubled Time
A Perfect Pandemic A Transsexual Transition in a Troubled Time A Novelette by Alexandra Rios Text Copyright Reserved © August, 2021 Dedication Transgender Day of Remembrance is a solemn occasion. I am offering “A Perfect Pandemic” for free as an antidote to the fear, phobia, discrimination, d... Read full Story
the greatest liar 2021-11-16 5,147 Teen (18+) Crossdresser Group Sex Big Tits Bareback Creampie Big Cock gangbang domination Guy Fucks Shemale Interracial double anal webcams
0%
Latex succubus
The lights of the city obscured the supposedly brilliant starlight in the night sky, leaving only dim and scattered scattered stars adorning the gloomy night sky half-covered by dark clouds, and the crescent-like crescent moon guarding it in the distance makes the night seem less empty Lonely. Mayb... Read full Story
Alicexiao 2023-01-06 4,347 Crossdresser Cumshot Creampie Fetish domination Guy Fucks Shemale high heel boots
85%
BANGING AROUND BANGKOK
BANGING AROUND BANGKOK: THE AMOROUS ADVENTURES OF CAITLIN "MEOW" MORRISON after living and working in Thailand/SE Asia for many years i decided to write an erotic story based on some of the people i have known, venues and places i have been, and the P4P night-scene where i spent way too much... Read full Story
bkkldby 2019-06-17 14,104 first time Teen (18+) Amateur Group Sex Big Tits Cumshot Outdoor Bareback Blowjob Big Cock Asian lesbian public place
100%
From a 50's virgin to a Mature good for all
***Prologue - Confessions: Every day since I offered my virginity, I put myself in the shoes of a woman. The little town where I live forbids me to show myself socially. However I made myself an accomplice, my epilator who receives me after closing. Since my new beginning, male masturbations are not... Read full Story
hippocampus_171 2023-01-11 4,347 Stockings Crossdresser Amateur Group Sex threesome Big Cock domination Mature foursome Homemade cum in mouth shemale + shemale milfs
100%
Hung Trans Lesbians Fuck Two Ladyboys
Note 1: If you like Transsexuals, Trans Lesbians, Asian Ladyboys, Big Cocks, Extreme Cock Sucking, Anal Fucking, Anal Fisting, Semen Swallowing, Role Play, Orgies, BDSM, Cock Sounding and Foot Fetish this story is for you. Note 2: All the characters are over 21. The names are fictitious, but some... Read full Story
darrell 2022-01-03 4,337 Group Sex Big Tits Cumshot Bareback Fetish Blowjob Big Cock Asian Ladyboy Sex Toys Mature cum in mouth shemale + shemale
100%
tiffanylondontv becomes a captive slave prisoner and whored out
I had connected with Master X on a BDSM Fetish contact site. He was the owner of a fetish store and he said that he had been on the BDSM for several years. He had carefully studied my own profile and had seen that I had an immense interest in being used like a slut, being covered head to toe in... Read full Story
__tiffanylondontv__ 2022-09-20 4,484 Crossdresser Amateur Group Sex Fetish Latex Mature
100%
delicious virile male flesh
Tasted delicious virile male flesh… The breeze caressed my swollen nipples giving me pleasant shivers. The two glasses of Riesling had also contributed to my excitement. My crotch was burning as if the disappearing sun had blown all its thermal energy into me. Under my fine lace panties, purple o... Read full Story
hippocampus_171 2023-04-23 4,992 anal Small Tits Amateur Creampie Blowjob Mature small cock big ass feminisation cum in mouth gaycd virile
85%
THE WEATHERGIRL BY B-MAN
PART 1: A COURTESY CLIENT BLOWJOB Three weeks into my gig at Coxon & Dicster had been a blast. At first, a few of the girls had some reservations about me working there because I wasn't transgendered myself but I guess I won them over with my naturally cheerful personality. At least,... Read full Story
bennyx709 2015-07-29 7,507 Crossdresser hardcore ass fucking cd
66%
A different couple
I am Hans, as I already mentioned in my previous story, I am a mature guy (47 years old) who came to the Island of Tenerife more than two decades ago. I am a drinker, a womanizer and a gambler. In these more than 20 years I have seen them in all colors. I have made a lot of money and lost as much, I... Read full Story
lkusex 2021-03-08 5,682 Amateur Big Tits domination
100%
My 1st Time was Not the Only Time.
One late night after hitting the slopes and partying I left my friends birthday party feeling extra horny. It was about 6 or 7 in the morning now and after having no luck finding an escort I responded to an ad on craigslist posted by a trans woman. I figured two things, this dick isn't going to suck... Read full Story
LesFuax 2019-02-16 9,122 first time Small Tits Amateur Latina Bareback Creampie threesome Blowjob Big Cock ass fucking barebacking barebackedshemales first time with a tranny raw anal raw dick raw fucking firsttime
100%
Camming Down the Rabbit Hole Ch. 09
As per my previous mornings recently, I stirred and rubbed the sleep from my eyes, that delicious feeling of my silk night ware stretching over my taught nipples and my morning wood throbbing in its lace enclosure. The urge to touch myself was palpable, it seemed no matter how hard I came the night ... Read full Story
Dani_does_Dallas 2022-03-22 3,438 Stockings Crossdresser solo Amateur Cumshot Masturbation Lingerie Sex Toys Homemade self sucking pov cum in mouth webcams
100%
The Seductive Seed of a Tranny MILF
The Seductive Seed of a Tranny MILF SugarandSalt Jackson got home and immediately curled up in bed. He didn't want to move for the rest of the weekend. He'd finally worked up the courage to ask a co-worker out at work. She politely rejected the invitation. Then later on in the day, Jackson spo... Read full Story
Gwapo67 2022-05-03 7,790 Bareback Creampie Shemale Fucks Guy Blowjob Big Cock Mature cum in mouth
100%
Tony to Tanya Part 3
Sarah finished applying make-up to Tony's face. It was mostly subtle, just enough to highlight his eyes and cheeks. The only part that wasn't so subtle was the lipstick; bright red. He was already dressed up in a beautiful black dress that left his back and shoulders exposed and only went down to... Read full Story
shemale lover 2011-12-19 4,554 anal cum oral
100%
Threesome goes clubbing
Ft. Lauderdale is probably the most LGBT friendly city on the east coast. So many nice restaurants and clubs that welcome all and have many LGBT employees as well. Lydia and I have been married several months, we had met Joanne an absolute amazing transgender girl during a weekend trip to the Baha... Read full Story
Jon Paul 2021-07-08 5,262 Big Tits Cumshot Bareback Creampie threesome Guy Fucks Shemale cum in mouth
93%
Interracial Sissy Story
(Some prior notes about me, this story and my writings: If MALE bisexuality, crossdressing or interracial sex bother you, don't even bother reading this further, much less commenting. Many have had secret fantasies about what it would be like to be the opposite sex, during sex. Some of my influences... Read full Story
shemale lover 2015-05-01 15,231 first time ass Cumshot suck cd sissy make up
90%
Saving My Marriage
I love to write Erotica. For story requests please send me a private message or email noirenoire10@gmail.com It was our anniversary. Today made five years that my wife and I have been married and we were taking a road trip to celebrate. I chose our destination but I let her choose all of our a... Read full Story
therefill05 2021-02-16 6,104 Cumshot Bareback Creampie Shemale Fucks Guy threesome Blowjob Big Cock Ebony domination Sex Toys cum in mouth
100%
My story; don’t know which one... English version (1)
I notice that the're not many french language readers so have I decided to publish an English version End of the 80s; a tough time for a young reporter travelling thousands of km's for a crumb of titbit. A new event and more pressure every day for me. Seeing me in this floundering state during a ... Read full Story
hippocampus_171 2022-07-21 3,558 Small Tits Crossdresser Amateur Bareback domination Sex Toys Mature Homemade
100%
Santa Likes Shemales Femboys
Did you know Santa Clause is real....and he likes shemales femboys??!I It happened last Christmas Eve. I fell asleep watching the snow fall just outside my window. I was comfy under my layers of warm blankets I clutched tightly, in the black lace panties and red lingerie night dress or nighty I wear... Read full Story
Chrissy Tunnell 2022-12-01 3,634 Small Tits Crossdresser Amateur Bareback Fetish Big Cock Ladyboy Lingerie domination Guy Fucks Shemale Mature
50%
lust of a sex-agenarian nana-pops
Frenzied lust of a sex-agenarian nana-pops; between dream and reality I had never fantasized of a manly man, even after offering my virginity; to a fabulous sissy. Before my new Era, my fantasy preferences were always with glabrous he-she’s, same about my relationships after… BUT BUT BUT… My last t... Read full Story
hippocampus_171 2023-07-09 4,700 anal Small Tits Amateur Group Sex Masturbation Guy Fucks Shemale Sex Toys Mature small cock big ass sissy femboy
100%
A Series of Perverse Dreams, Part 2
Three or four days had passed since my torrid alley way dream. Hannah had recently come over to share a few glasses of wine and a steamy fuck session in the shower. She had definitely embraced the ways of edging I had shown her because when she came in my mouth I could barely contain the massive amo... Read full Story
KaceyKlarissa 2024-02-29 4,427 Crossdresser Big Tits Cumshot Bareback Fetish Blowjob blonde Big Cock big ass Futanari bukkake sissy cum in mouth
100%
Intense
Holding to my word, I didn't let the incident with Billy and his friends scare me away from Bailey; I kept seeing her, even after the beating I took. To be honest, I'm not sure if he was trying to lay low or what, but Billy seemed to keep his distance from me for a while...thankfully. Bailey and ... Read full Story
Verpa 2019-10-21 10,770 Big Tits Cumshot Bareback Creampie Shemale Fucks Guy Blowjob Big Cock cum in mouth
50%
A Perfect Life
The reasons I am not writing this myself. I have finally convinced someone to do it for me. She promised to post it on the Internet, but only as fiction. I suppose it is a bit unbelievable. It all started with the best of intentions. I had married my love while we were still in college. She... Read full Story
shemale lover 2012-05-05 12,575 transgender
89%
Fem Firm 2 -The Weathergirl
PART 1: A COURTESY CLIENT BLOWJOB Three weeks into my gig at Coxon & Dicster had been a blast. At first, a few of the girls had some reservations about me working there because I wasn't transgendered myself but I guess I won them over with my naturally cheerful personality. At least,... Read full Story
bennyx709 2016-11-14 18,006 big dick anal sex suck Blowjob cock sucking workplace
50%
Lust and Love with Leona
This is a work of fiction. * The days after I fucked with Leona I spent alone. She has told me that she was going for shoot in the Bahamas for a week. I was a man who had everything in terms of material comforts, and there was not a girl I couldn't pull in a bar. But I found that I could not s... Read full Story
shemale lover 2011-10-07 4,574 hardcore celebrities oral extreme
80%
TG Girlfriend moves in (part 2)
My wife Lydia and I have been married about 9 months, we have a very close TG friend, Joanne, that lives next door and every once in a while, we get together, and all go out and enjoy. We have had sex together, and when Lydia is away Joanne, and I are together at every opportunity. Joanne and I work... Read full Story
Jon Paul 2022-01-21 3,464 Big Tits Cumshot Bareback Creampie threesome Blowjob Shemale and Girl Guy Fucks Shemale
100%
Lola Chapter 5
Lola chapter 5 Summer vacation was coming to an end. Most of the time we had been to ourselves, mostly at home but also a couple of shorter trips. Beer tasting in Stockholm's archipelago, a trip to the west coast, overnight stays in hotels, everywhere we were received like any other couple. A fam... Read full Story
BellaBeau 2023-10-30 5,739 anal Cumshot Latina Bareback Creampie threesome Shemale and Girl Lola
60%
The Creators: Book One by
Chapter One: The Life Giver BRANDON My twin sister is dead, but she’s not gone. Death is a tragedy in the remote village of Towerhead, but it’s not a rarity. Farming accidents, disease, famine, natural disasters, you name it, it kills people in Towerhead. So, six years ago, when the oxen-pul... Read full Story
sagga 2018-09-18 30,361 Teen (18+)
100%
Camming Down the Rabbit Hole Ch. 12
We woke up many hours later, still intertwined, my morning wood throbbing as Ellie slid inside my panties and wrapped her hand around it. This was a much better way to wake up than usual, and we proceeded to have a really relaxed slow fuck. She reached a much more low key orgasm but I knew I wouldn’... Read full Story
Dani_does_Dallas 2022-05-09 5,289 Crossdresser solo Amateur Cumshot Outdoor Masturbation Blowjob Shemale and Girl Sex Toys self sucking pov cum in mouth webcams
100%
How My Wife Became a Swinger
Hello, my name is Jackson, Jack for short, and I'd like to tell you about my wife and I and how we became swingers. I've changed the names of people and places to preserve privacy. Just so you know this does involve male on male sex and inter course with a transsexual. So let me begin. For the fi... Read full Story
Loveto 2011-10-12 8,605 anal bisexual gay strap-on
50%
How My Wife Became a Swinger
Hello, my name is Jackson, Jack for short, and I'd like to tell you about my wife and I and how we became swingers. I've changed the names of people and places to preserve privacy. Just so you know this does involve male on male sex and inter course with a transsexual. So let me begin. For the fi... Read full Story
shemale lover 2011-11-13 5,199 Group Sex Cumshot sucking doggy style
80%
Office Policy
“Ok ladies and gentleman, please put your hands together for the beautiful and talented Erika!” the DJ’s voice rang out over the thumping alternative beat as the object of my lust strutted to the stage. Erika’s saucy red curls bounced on her head and on her soft porcelain whi... Read full Story
shemale lover 2012-08-30 8,456 anal ass sucking threesome tits fingering sex blondie
100%
Transsexual Sisters Chapter 6
Part 6: A Party to Remember MICHELLE AND NICOLE MAKE A CAREER CHOICE After their tormentors were jailed, Michelle and Nicole felt relieved and happy for the first time in weeks. Whether from curiosity, respect or sympathy for their ordeal they became very popular around the USC campus. They we... Read full Story
shemale lover 2012-09-08 4,145 Cumshot sucking threesome Shemale and Girl deep throat
50%
A Revenge Fuck
It had been a long day. I had fought the traffic after a miserable week to get home early and surprise my wife for what was to be a romantic weekend. But as I pulled up to the house my heart sank. I saw a bright red motorcycle in the drive way and something inside told me, "This isn't right!&qu... Read full Story
shemale lover 2012-06-03 11,162 shemale oral sex Interracial
0%
Tara's Adventures
Part 1 I had met them on line. Marla 1st then her owner Mistress Olivia. We chatted for well over a year and had met for drinks. They knew of my submissive fem side and we had planned meetings on several occasions but things always developed that upset them. Then a period of time developed whe... Read full Story
shemale lover 2012-08-11 5,240 anal Group Sex oral domination sissy
100%
Womanhood for Jenny
The muted alarm-clock brought jenny awake instantly. She reached over to shut it off. Being ever so careful not to disturb Master, she slipped out of bed and gazed lovingly at the sleeping man. From their earliest intimacy, He had accepted her completely as a woman, His woman, not a trans-gendered m... Read full Story
shemale lover 2012-10-07 5,844 hardcore Sex Toys tg
96%
Family Frolic
FRIDAY My sister and her husband wanted to take a few weeks off in the sun and asked me to look after their kids for a while. I'd move out of my tiny apartment and into their house for the duration. As I was still living off my severance and they had a nice spread with an indoor pool and a h... Read full Story
shemale lover 2012-01-14 30,955 strapon porn
50%
Freak House Superstar Come Fest
Kiki and Ty Blaze were doing their thing. They were living on their love and passion, literally. The couple had taken their love, passion and desire to please one another and turned it into their livelihood. They had become stars in the world of underground porn. Their production studio, Nasty Nigga... Read full Story
shemale lover 2012-02-01 6,332 anal shemales Group Sex