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 4,870 Bareback threesome Blowjob blonde Big Cock Sex Toys Ass to Mouth
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 12,235 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
66%
Be My Bitch
After a long day at work, I get in my car, and look forward to the long drive home. It gives me time to unwind and relax. I try to forget about the hectic office and concentrate on my beautiful girlfriend waiting at home with that warm smile that she greets me with when I get there. However, tod... Read full Story
Go Balls Deep or Go Home 2018-08-06 31,787 Crossdresser Outdoor Bareback Blowjob Big Cock Ladyboy Lingerie domination Guy Fucks Shemale Interracial Sex Toys Ass to Mouth cum in mouth
90%
Sissy Slut and Stepdads
Frank was pumping me hard and his huge cock seemed to have grown and become extra hard. I am so thrilled that way he enjoys fucking my ass with such passion. I would almost think he was in love with me if this relationship wasn't so bizarrey. It’s ironic that as a male I always get total humiliation... Read full Story
Regina10 2020-11-30 9,556 Crossdresser Bareback Creampie Fetish Blowjob blonde Big Cock Ladyboy Lingerie Guy Fucks Shemale Ass to Mouth double anal
100%
I fucked the hotel handy man and he had a monster cock
I was on vacation in a new town and decided to stay at this new hotel. I heard it was the best and the location was close to some sites I wanted to explore. I enjoyed my stay there, especially one evening when my air conditioner stopped working, and the hotel guy came to fix it. He looked so hot tha... Read full Story
Madison Heights 2023-09-05 7,186 anal ass Big Tits Cumshot Bareback Creampie Fetish Uniform piss Ass to Mouth cum in mouth monster cock watersports
92%
MY Party Favor Fantasy
My Party Favor Fantasy A fictional story built around an old fantasy of mine I ran a notice on one of those sex sites that said” Help me fulfill my fantasy and I bet we take care of some of yours also. Hi there, I am Penny and I am a total bottom trans w... Read full Story
pennypenny 2019-01-08 7,568 Stockings Crossdresser Group Sex Cumshot Masturbation Bareback Creampie Fetish threesome Blowjob Big Cock gangbang Lingerie redhead domination Guy Fucks Shemale Sex Toys Ass to Mouth cum in mouth double anal
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 14,468 first time Teen (18+) Amateur Group Sex Big Tits Cumshot Outdoor Bareback Blowjob Big Cock Asian lesbian public place
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 4,695 Group Sex Cumshot Shemale Fucks Guy Blowjob blonde Big Cock Asian Shemale and Girl Sex Toys Mature Ass to Mouth shemale + shemale
37%
Wedding Night Surprise
its my big dream to marry one women in our night wedding in the bed when i start to make her naked a discover i big dick between her legs wow she demand me to hide this secret and i accept ans she abuse to take me and more...... Read full Story
BIG DICK HUSBAND 2018-12-06 15,706 Big Tits Cumshot Bareback Creampie Shemale Fucks Guy Blowjob blonde shemale Big Cock Asian Ladyboy Lingerie domination Mature Homemade Ass to Mouth Surprise Weddings night husband
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 11,402 Group Sex Big Tits Bareback Creampie Blowjob blonde Asian Ladyboy Shemale and Girl Guy Fucks Shemale Ass to Mouth cum in mouth double anal
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 4,266 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%
Additional Thoughts on Sodomy
Although, in the world (or worlds?) of pornography and erotica, it is politically incorrect, perhaps, to suggest that the body, whether male or female, is not built for anal intercourse, the fact is that anyone who has participated in this act (especially on the receiving end) or who has enjoyed wat... Read full Story
shemale lover 2011-10-05 4,225 Creampie sperm anus
65%
Marcia Goes Back to School
Marcia was painfully nervous. She hadn't been able to eat very much in days. The upside was she was even skinnier which would make Mistress and her husband very happy. She'd always been thin and on the diet Mistress Carol had her on she was already thinner than she dreamed possible. Her anxious stom... Read full Story
shemale lover 2012-12-19 10,855 Masturbation Blowjob blonde ass fucking big boobs
50%
trans=demic
Trans-demic Chinese Flu Sam Wong read the email from Josh Epstein, the partner in charge of the fiendishly complicated real estate deal that had consumed the last three months of their lives. “You’re going to have to close this deal without me. I’m sick as a dog, and my wife just called an ambu... Read full Story
the greatest liar 2024-09-09 1,461 anal Small Tits Bareback Creampie Asian Guy Fucks Shemale small cock Ass to Mouth cum in mouth
100%
The Game 2
That next morning again Ada and I went down for breakfast and the table was smaller, It wasn't as grand as it had once been and to every guy at the table was now at least two girls. We had our normal breakfast and for once there seemed to be a little more chat between everyone, I think after bei... Read full Story
chris1989r 2022-01-24 4,792 Amateur Cumshot Bareback Shemale Fucks Guy Blowjob blonde Big Cock Asian domination Guy Fucks Shemale Ass to Mouth cum in mouth shemale + shemale
96%
A Night of Lust
I was out at a night club with a few friends, and we were there for for a while before I noticed this sexy, rather short girl across from me at the bar looking over. I could tell, even from this distance that there was something special about her, I wasn’t sure what that was quite yet though. The mo... Read full Story
JessicaEdwards 2018-08-07 18,661 Stockings Amateur Cumshot Masturbation Bareback Creampie Shemale Fucks Guy Blowjob blonde Big Cock Lingerie deepthroating Guy Fucks Shemale cum swallowing deep throat deep penetration cum swapping pov Ass to Mouth cum in mouth anal fuck sloppy virgin ass
100%
Sweet Encore
I was alone tonight and feeling just a bit paranoid as I listened to the soft music. The soothing sounds put me in a seductive mood, but It seemed that all my lovers were too busy for me, or they had other plans. Uncle Barney and my detective were probably home being dutiful husbands. Bo was under h... Read full Story
Regina10 2024-05-09 3,610 Crossdresser Big Tits Bareback Creampie Blowjob blonde Big Cock Guy Fucks Shemale big ass Ass to Mouth
100%
Sissie Slut's Windows of Womanhood
I flash back to my first time with a grownup adult at the tender age of16 . I was so nervous now that we were here in the motel room. I was nervous for so many reasons. I lied to my family and told them I was staying at a friend’s house. Instead, I'm here with Mr. Joey in a motel room and he was my... Read full Story
Regina10 2021-02-22 6,908 Crossdresser Bareback Creampie Fetish Blowjob blonde Ladyboy Lingerie Guy Fucks Shemale Ass to Mouth cum in mouth double anal
100%
Regina’s Double threat.
Hello guys, I recently ran into a former hater who was no longer the hater I had met years earlier. In fact, he had only treated me so horribly because of his own inner dark desires. When we met a few years ago at one of the clubs, he had been very abusive to me. He went out of his way to say hurtfu... Read full Story
Regina10 2022-02-08 3,309 Big Tits Cumshot Bareback Creampie Fetish Blowjob blonde Big Cock redhead Guy Fucks Shemale Ass to Mouth double anal
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 6,384 Teen (18+) Crossdresser Group Sex Big Tits Bareback Creampie Big Cock gangbang domination Guy Fucks Shemale Interracial double anal webcams
75%
Flowers in the Heart
Chapter 1 "Hey Scott, Fauna kind of likes you," Jenna said, snickering. "Hey Jenna, it hard to hear yourself over that echo?" Scott said as he caught the football, and then heaved it back to Ronnie. "Huh?" Jenna asked, puzzled. "Yeah, your head up your ... Read full Story
shemale lover 2012-11-11 10,680 anal tranny Cumshot oral
100%
Big cock heaven.
I live in Vancouver and saw a beautiful trans escort online and couldn’t resist setting up a meeting. I met her at a hotel and she was just as beautiful in person as online. She was Asian and had the most wonderful big tits and ass. Her cock was a solid 8 inches, uncut with a big mushroom head, whic... Read full Story
Eyecandy64 2024-02-06 6,748 anal Bareback Creampie Shemale Fucks Guy Blowjob Big Cock Asian
100%
Sarah fucking in vienna
Sarah in Wien , sie nennt mir ein mir bekanntes Hotel in der Innenstadt, sowie eine feste Uhrzeit! Überpünktlich bin ich Vorort , komplett glatt , unter der Anzugshose einen schwarzen engen Nylon Slip , sneaker weißes Kurzarm Hemd, guter Duft , klopfe ich etwas nervös an der Zimmertür! Von innen k... Read full Story
Sarah Diener 2023-08-30 2,107 anal Crossdresser Amateur Cumshot Bareback Creampie Blowjob blonde Lingerie Guy Fucks Shemale sissy Ass to Mouth cum in mouth
100%
Feriengruss 20.07.24
Erneut ging es Outdoor, dieses Mal aber an die Thur zum FKK Baden. Nicht am bekannten Platz in Bischofszell, sondern an meinen geheimen Platz, zwischen Kradolf und Bischofszell, unterhalb von Halden. Ich habe erneut mit 5 verschiedenen Herren abgemacht, die mir in gut geplantem, zeitlichem Abstand... Read full Story
Cheryl_F 2024-09-03 242 anal Small Tits Amateur Cumshot Outdoor Bareback Creampie Blowjob blonde Big Cock Ladyboy pov Ass to Mouth
100%
Sarah die Nutzstute I.
Sarah hat sich wieder angekündigt , nachdem man jetzt weiß wie weit man mit dieser heißen Stute gehen kann, packe ich ein paar Sachen in meine Tasche und mach mich auf den Weg ins genannte Hotel ! Locker in Jeans, Polo , Pulli und Sneakern klopfe ich an, höre wie die Stute an die Türe stöckelt, bi... Read full Story
Sarah Diener 2023-09-14 2,685 anal Stockings Big Tits Bareback Creampie Blowjob blonde Big Cock Lingerie domination big ass Ass to Mouth cum in mouth
100%
Beefy Buns
It's hard to get good help. Probably, that's true in any business, but it's especially difficult to find decent employees in the fast food racket. Believe me; I've tried. I manage the local Beefy Buns franchise--burgers, fries, and shakes is our mainstay, but the menu also features fish and chick... Read full Story
shemale lover 2012-04-22 6,361 anal sex Creampie blonde shemale
33%
Duel With the Devil, Chapter 20 of The Greatest Liar
Duel With The Devil This is a work of fiction. All characters (including the narrator), celebrities, places, residences, neighborhoods, restaurants, legal agreements and proceedings, events and incidents are either the products of the author's imagination or used in a fictitious manner. Any r... Read full Story
the greatest liar 2023-07-19 4,345 anal Bareback Creampie Ebony Guy Fucks Shemale post-op celebrity post op sex
100%
A Fairy Tale Part 2
=-=-Chapter Six-=-= I woke up sometime later and I was feeling better, even a little hungry actually, and I wanted a shower and I needed to pee and...I cocked my head as I heard the unmistakable sounds of Mistress Stacy's bed moving. She had a large one, king sized, with old springs or somethi... Read full Story
shemale lover 2011-12-06 6,975 Creampie Big Cock ass fucking
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 20,594 Big Tits Cumshot Bareback Creampie Shemale Fucks Guy threesome Blowjob blonde Big Cock Ebony Uniform domination cum in mouth
100%
My first TG lover
I first met Holli at the gymnasium of our apartment complex. Since it was around 6:00 am on a Sunday morning, I didn’t expect to see anyone that early. At first just like we all do, the customary good morning, small talk, and it usually stops there, but there was just something that drew my attentio... Read full Story
Jon Paul 2022-07-01 8,045 Amateur Bareback Creampie Shemale Fucks Guy Blowjob Asian Guy Fucks Shemale
100%
The Wonderful Adventures of Miss K
Miss K sat near her bedroom window in her pink silk robe, staring off into the late morning skyline in the distance while she held a cup of hot chocolate in one hand and ran the other through her waist length bleached blonde permed hair. The indirect sunlight lent the dark chocolate skin on her sili... Read full Story
shemale lover 2011-12-03 6,136 anal oral fingering long dick
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 5,050 Bareback Creampie Shemale Fucks Guy Blowjob Big Cock Mature cum in mouth
100%
Young Hercules: Versatile Stud by The Fan
Prometheus Academy. It sat atop a hill, dominating the vast region of Thessaly, Greece. It was the most prestigious school in the area. The most famous men and women of the world came there to get their education. The sons and daughters of kings and queens, ... Read full Story
shemale lover 2011-12-01 3,521 anal Creampie jacking off
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 18,325 big dick anal sex suck Blowjob cock sucking workplace
75%
Passion in the Rough
Tonight, I was searching in vain for a parking place close to the club, but unfortunately, I had arrived late and there were no empty spaces close by. I drove around and went down several streets in the same block until I found an empty spot. That was perfect I thought as I found a parking place and... Read full Story
Regina10 2024-04-27 3,770 anal Crossdresser Big Tits Outdoor Bareback Creampie Blowjob blonde Big Cock Ladyboy gangbang Guy Fucks Shemale
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 4,697 Group Sex Big Tits Cumshot Bareback Fetish Blowjob Big Cock Asian Ladyboy Sex Toys Mature cum in mouth shemale + shemale
60%
Brotherly Love, Sisterly Love Chapter 2
"RACHEL" My twin sister, and sometime brother, and I had been experimenting sexually with each other and crossdressing together for around a month, growing to love and to perfect our new feminine personas until they became the ones we thought of as our true selves. Whenever our parents ... Read full Story
shemale lover 2012-09-28 6,825 Cumshot Fetish oral sex cum swallowing
90%
Collette's Property
I've been Collette's lover for four years now and this gorgeous, incredibly kinky woman still continues to amaze me. Our sex life would be unimaginable to most people, even those who live lives embracing BDSM and other fetishes, and it's Collette who makes it happen. Of course everything is a trade ... Read full Story
shemale lover 2012-12-19 8,224 anal Crossdresser Blowjob domination ass fingering
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 31,397 strapon porn
85%
Transsexual Cheerleader
Transsexual Cheerleader Marcus, the football team quarterback, was well known at the university as the "most datable on campus", and he had had his share of women. From the nice virginly freshman, to the hottest senior whores. It was no wonder that he was so popular. 6'4, 240 pounds of pur... Read full Story
shemale lover 2012-05-13 3,990 anal sex Creampie Blowjob
100%
Claudia Coming out adventure part 1
*Author's Note: This story starts off being told in First person and after awhile the story shifts to third person* Hello everyone, my name is Claudia I am a Cross dresser who one day hopes to be transgendered, although I do not want the surgery, I am looking to eventually live my life full... Read full Story
MissClaudia 2015-01-04 6,156 tranny Stockings suck Creampie ass fucking doggy style Latex
75%
Just another Saturday appointment at my Hair Salon
After I applied my makeup and jewelry, the young salon clerk helped me slip into a skin-tight black latex catsuit, with a crotch zipper from front to back. The 2 beauticians then used shiny duct tape to secure my wrists to the salon chair arm rests. They then spread, elevated, and taped my ankles to... Read full Story
PurpleFlower9222 2020-12-16 5,003 Amateur Creampie Fetish salon Colored hair bondage fuck
100%
End of the Beginning
Jamie stood there with her mouth hung open for a moment. She was utterly shocked. How could it be true? Chloe and Josh met at basic, how could they be engaged? It had only been a month since Jamie left. Tears stood in her eyes but refused to fall. This was not at all what she had envisioned. “... Read full Story
shemale lover 2012-04-14 2,624 anal Creampie oral
75%
Rebound
My story is nothing new, like most girls who used to be boys I knew from an early age that I was different to all my school friends. My dad was a thug of a man, who enjoyed the physical battle of the rugby pitch as much as the post match booze up, but I took after the mother who died giving birth to... Read full Story
shemale lover 2011-11-25 6,417 anal Creampie oral
0%
The Greatest Lie Part 16
As soon as we were safely back in our hooch, I retrieved the iBook from its hiding place under the floor and opened up Spartan's main Excel spreadsheet. I re-sorted the list against the data from the last three weeks of our frustrating field work, by district, language group, age, and every other ca... Read full Story
shemale lover 2012-01-20 5,202 first time femdom crossdressing
88%
Alex and Jon
Alex was not beautiful, but had a sexy attractiveness that most could not help but take a second look. This was the case with Jon as he searched adult Friend-Finder ads for someone that would satisfy his desires and dreams of a companion. Alex, a transgendered Filipina girl, had the bronze skin colo... Read full Story
Jon Paul 2022-09-21 5,607 Group Sex Cumshot Bareback Creampie Shemale Fucks Guy Blowjob Asian Ladyboy Guy Fucks Shemale cum in mouth
83%
How Kevin Became Finesse
Monica went out with JJ! He was a black buff guy who taught karate where she took the kids. He drove a yellow corvette and liked to wear shirts with the sleeves cut off - to show off his big tattooed arms! All the young blonde girls were on his jock, but he had the eyes for Monica. She kept protesti... Read full Story
Kevyn-JeanneHarris 2015-12-20 4,742 sissy cross dresser cuckold
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 6,095 anal Cumshot Latina Bareback Creampie threesome Shemale and Girl Lola
100%
Fender Bender Chapter 7
The main Characters are as followed: My name is Robert, but when I am dressed I call myself Vicki. I am 5'9" 160 pounds, blonde hair and blue eyes. I turned 18 a few months ago. Gary is almost 6', 185 pounds. He has short blonde hair and dark blue eyes. He has a nice tasty 7 1/2 inch cock... Read full Story
shemale lover 2012-07-27 3,316 Creampie ass fucking domination oral sex sissy
75%
A Couple And A Shemale Encounter
Not long ago I was sitting home alone on a Friday night with nothing much to do and feeling horny so I decided to go out. I showered, misted myself with my favorite perfume, put on a sexy black bra, rolled on a silky new pair of jet black sheer to waist pantyhose, slipped into a tight, very short, l... Read full Story
shemale lover 2011-08-26 5,422 anal Creampie shemale
80%
Owned sissy girl
I met the mature dominant couple that I now call Mummy & Daddy on the internet. Their ad said they were looking for a full-time live-in mature sissy plaything. After we made contact they invited me to their house. I was instructed to bring any sissy clothes with me and to refrain from orgasm for... Read full Story
Andrellina 2015-09-23 29,470 anal ass rimming cd sissy
100%
First Date With Daddy
My Dream Date. It hasn't happened yet, but a girl can hope, this story is very short story based on my fantasy's. It was Sunday night and I had my first date lined up with daddy. We hadn't met, but we had spoken online at depth and exchanged numbers. I had sent him a couple of pic... Read full Story
SEXYBADGIRL 2023-03-17 5,311 Crossdresser Bareback Creampie domination
71%
Joanna Tranny Prostitute
Joanna stood on the street corner and casually shifted her posture from one leg to the other. So far it had been a quiet evening for her with few punters around. Not many girls were plying the streets either. She’d had one customer earlier. He had been an Asian guy in a Toyota who’d stop... Read full Story
shemale lover 2014-06-19 7,266 shemales Masturbation voyeur
100%
Joanna the Tranny Prostitute
Joanna stood on the street corner and casually shifted her posture from one leg to the other. So far it had been a quiet evening for her with few punters around. Not many girls were plying the streets either. She’d had one customer earlier. He had been an Asian guy in a Toyota who’d stop... Read full Story
Joannacd1 2011-11-07 4,544 tranny Crossdresser Ebony
33%
Being Barbi's Bitch
After ten wasted years of foolishly trusting in love to 'cure' me of my femininity, I had only just begun to re-embrace the sissy inside me when something made me reach out to an old friend. What made me do it, I really don't know. Although I was once again revelling in even the smallest aspects of ... Read full Story
shemale lover 2011-10-01 9,206 Stockings sucking domination
58%
My real story
I couldn't believe it. Here I was in bed with an older man – and one that I most wanted as he lay there sated by my ministrations to him. It had all started two weeks earlier when I had posted an ad on Craigslist. Up until this particular posting I had always been pretty bland..."Willi... Read full Story
shemale lover 2012-06-10 6,565 hardcore Cumshot bdsm oral sex