Sort by
Relevancy

Free Stories

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 4,358 Stockings Crossdresser Amateur Group Sex threesome Big Cock domination Mature foursome Homemade cum in mouth shemale + shemale milfs
100%
Shopping plus extras!!!
Hi, so as you can probably imagine I buy a lot of underwear and have a few favourite places to shop. My favourite by far is Ann Summers. The range is great and the staff are so helpful . Anyway back to the story. So I decided to go get some new underwear to see in the new year, I got myself up and d... Read full Story
Samantha Jewels 2023-01-06 4,354 Crossdresser Amateur Cumshot Fetish threesome Blowjob Big Cock Lingerie Shemale and Girl domination Guy Fucks Shemale Ass to Mouth cum in mouth
100%
My Love Letter To Joanna Jet
I await my goddess on my knees, my heart pounding in my chest as I hear the sound of your footsteps outside my door. You knock and I spring to my feet, opening the door. You enter, pushing me aside and closing the door behind you. You are radiant, tall and curvy, with long black hair, smooth cara... Read full Story
TgirlLover4Life18 2022-04-12 2,276 Big Tits Cumshot Bareback Creampie Shemale Fucks Guy blonde Big Cock Lingerie Mature Ass to Mouth
100%
KING OF TRANNY CHASERS ENTRY 2
LAST YEAR TO CELEBRATE MY BIRTHDAY I DECIDED TO FULFILL ONE OF MY SEXUAL FANTASITES. I HAD BEEN WITH 2 CIS WOMEN SEVERAL TIMES BUT NEVER HAD I BEEN WITH 2 TRANNIES. MY BIRTHDAY WAS ON A FRIDAY SO I SPENT THAT DAY AND THE NEXT CELEBRATING WITH MY FAMILY AND GINA..THAT SUNDAY I SET UP AND PLANNE... Read full Story
Ghostface drillah 2024-07-04 1,028 anal Amateur Group Sex Big Tits Cumshot Shemale Fucks Guy Fetish Big Cock Guy Fucks Shemale big ass Homemade Ass to Mouth shemale fucks shemale
100%
From accidental trans porn addiction to a cum filled booty
One night when I was around 30 or so I was watching some porn, nothing unusual for a guy like me, aka a sex addict. Sex addiction is great if you’re Tiger Woods and swimming in poon, but for guys like me - regular, awkward, slightly handsome in a very boyish way, weirdos — it’s not that fun. We... Read full Story
CDJaneBooty 2022-04-01 10,059 first time Crossdresser Amateur Cumshot Bareback Creampie Blowjob Big Cock gay Homemade Ass to Mouth curious first time with a man
50%
How Sia Shemale Pune fucked me ...
I met Sia through ts-dating . Called her n went to meet her. When I saw her I could not believe that she is shemale n has got cock between her legs. My god so beautiful feminine. Her implants are very sexy n make her more beautiful... Then I paid her n we went to comfortable small bedroom. I d... Read full Story
Stud4Shemale 2021-02-19 5,693 Shemale Fucks Guy Blowjob Big Cock Asian Ladyboy big boobs cum in mouth shemale fucks male Indian Shemale Pune
56%
Big cock shemale from Pune, India
I just saw her profile on Planet Romeo, her name is ID is Kaynat / Muskan. I saw her photos and got attracted to her. I am always a big fan and lover of Shemales or TS. I called her and fixed appointment by negotiating with her for 2500 INR. I went to meet her, she stays in a condominium in ... Read full Story
Stud4Shemale 2017-05-22 95,925 Big Cock Asian Ladyboy Guy Fucks Shemale Ass to Mouth cum in mouth
85%
My Knight
I felt good as a looked around the club and watch the Queens on stage perform their acts. I felt like I belonged here among this faction of society. Drag queens and Trannies were my people and the only thing I regret is being in the closet and not having the courage to do it more openly. However i d... Read full Story
Regina10 2020-06-23 3,837 Bareback Guy Fucks Shemale Ass to Mouth shemale + shemale
50%
MA MAÎTRESSE MIRACLE
Sam tapota nerveusement ses doigts contre le verre à moitié plein. En règle générale, vous êtes censé boire un coup avec une gorgée, mais sa tolérance à l'alcool n'était pas exactement la meilleure et le bourbon dans la tasse servait vraiment plus de courage liquide à ce stade. Cela faisait ... Read full Story
Femboy 2021 2023-02-05 1,134 Stockings domination Sex Toys Futanari Ass to Mouth cum in mouth shemale + shemale
50%
J'ai enfin goûté la bonne chère/chair
Dépucelée en bon et du forme... Chose jamais osée depuis que je goûte la jouissance par tous les sens et dans tous ses sens... Je la découvris quand elle m'a sourit en guise de remerciement pour lui avoir cédé le passage dans la superette du bled où j'étais pour affaires. Sandales à ses pieds d... Read full Story
hippocampus_171 2022-11-09 1,068 Small Tits Amateur Shemale Fucks Guy Guy Fucks Shemale Mature Homemade Ass to Mouth Vintage cum in mouth
0%
SOUMISSION CIEL ⚧️ ⚧️
J'ai regardé les pieds de ma mère se frotter lentement les uns contre les autres, les nylons de ses collants produisant ce son distinct et délicieux pour lequel j'étais si faible. *Suisse* Un pied posé sur l'autre, bougeant doucement et lentement, se caressant dans un mouvement hyp... Read full Story
Femboy 2021 2023-03-18 807 Crossdresser Cumshot Masturbation Shemale and Girl domination Ass to Mouth
50%
Son fils se fait «punir» par maman
Les parents ont divorcé après que mon père ait été surpris en train de tricher. Après la séparation, j'ai choisi de vivre avec ma mère. Ma mère était très mécontente de la perte de son mari. Elle a commencé à fréquenter des hommes pour avoir des relations sexuelles. Tous les jours, je l'entendais se... Read full Story
Femboy 2021 2023-01-20 4,115 Stockings Crossdresser Fetish Big Cock Lingerie domination Guy Fucks Shemale Mature Ass to Mouth
100%
TO BE OR NOT TO BE – PART 2
TO BE OR NOT TO BE – PART 2 by Spanky de Bautumn Part 1. Sunny, Mel, and Shari learn they are going to New York to perform a play off Broadway and are really excited about it. Being a small troupe, we unseen members had to wear many hats. Unfortunately, there was just the two of us, Joe Donn... Read full Story
SpankydeBautumn 2021-02-22 3,651 Small Tits Crossdresser Cumshot Bareback Blowjob Big Cock Lingerie Guy Fucks Shemale Interracial cum in mouth
100%
Slut /W Bad Boy
I was excited as always because I was about to go out in public and hopefully I will meet some horny man with some money and get laid. Now, to make sure that I am a picture of femininity, I double checked my makeup in several mirrors from many angles. My lips were perfect and I made sure my cheeks b... Read full Story
Regina10 2020-12-04 7,071 Stockings Crossdresser Big Tits Cumshot Bareback Fetish Blowjob Big Cock Lingerie Guy Fucks Shemale pov Ass to Mouth
66%
TO BE OR NOT TO BE – PART 5
TO BE OR NOT TO BE – PART 5 by Spanky de Bautumn Part 4. Sunny made a life changing decision and in the process becomes better acquainted with Mark. On Monday, I met Mel and Shari at the theater at ten to run lines. I was confident that I knew my part for the first act. My concern was with m... Read full Story
SpankydeBautumn 2021-02-24 2,209 Crossdresser Cumshot Masturbation Blowjob Big Cock Lingerie Interracial
100%
I wanna fuck almost everyday
I can't stop thinking to be Double penetrated for two men at the same time.... It makes me feel I'm insatiable gurl... Two Big cocks mmmmmmm after been fucked for so long ... I will never go back... And certainly I will totally satisfied and addicted to it...... Read full Story
Bellasohot 2022-07-13 3,827 Crossdresser Amateur Latina Bareback threesome Big Cock Ladyboy Lingerie Guy Fucks Shemale Mature Ass to Mouth double anal
50%
My desire to be a woman,
My desire to be a woman, Natacha, tall and slender, stands in front of me. Her hair tied in a ponytail refines her face, emphasizing her Dominatrix profile. She wears a lovely nightie and a corset highlighting her magnificent breasts. She is perched on stiletto heels topped with thigh-high... Read full Story
sandratvtg 2024-07-04 879 anal Stockings Fetish Lingerie Sex Toys femdom travesti Vintage gode speculum donjon pussy pump castration play
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 15,391 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%
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 3,070 Big Tits Cumshot Bareback Creampie Fetish Blowjob blonde Big Cock redhead Guy Fucks Shemale Ass to Mouth double anal
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 2,295 anal Stockings Big Tits Bareback Creampie Blowjob blonde Big Cock Lingerie domination big ass Ass to Mouth cum in mouth
50%
Being Shemale
Every night I wear make up and dress up in a sexy lingerie. I stand in my balcony late night trying to lure men and women driving on the road. Last night a truck driver stopped near my house to inspect his vehicle. During his inspection he suddenly saw a long legged booty women in the balcony inf... Read full Story
babydriver 2024-06-04 2,454 Stockings Crossdresser solo Outdoor Ebony Asian Ladyboy Lingerie big ass sissy femboy
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 10,593 Masturbation Blowjob blonde ass fucking big boobs
100%
Male or Shemale, Still a Slut
Part 1 My name is Brandon. I'm 18 (still in high school), 5'5", white with black hair, and rather feminine. I'm really slim with barely any body hair. All this has combined so that I'm not so popular with the ladies, which sucks cause I am one horny son of a bitch. Luckily, I'm rather fond ... Read full Story
shemale lover 2012-12-20 9,314 Cumshot sucking blonde ass fucking Guy Fucks Shemale
97%
Never Wanted To Be Your Girlfriend Ch. 02
So, after being made up like a slut, left glued to a pair of silicon breast forms, and caught sucking-off my best friend, I was pretty sure my day couldn't get any worse, but I had come nowhere near the end of my torment, as Michelle now had something else planned that I was probably not going to li... Read full Story
shemale lover 2014-07-21 9,489 hardcore Cumshot suck Lingerie ass fucking
50%
The Ultimate Cock Ball Torture
I miss my cock. Sometimes. I had one once - one of my very own, connected right to me - but now it's gone. Never thought I would miss it. I'm sure you've guessed by now that I am a full transexual. I had the boob job and started hormone treatment years ago and felt much better as a shemale th... Read full Story
shemale lover 2012-04-29 3,591 anal sex oral sex
100%
David to Dee Chapter 2
His nipples had grown considerably over the last two months. Gina had been putting those little nipple suckers on him twice a day. Dave wouldn't be going to the gym anymore. Well, it had been a long time since he'd gone to the gym, anyway. Since Gina had had him shave his entire body, last spring... Read full Story
shemale lover 2012-07-30 5,781 anal sex Cumshot oral sex rimjob
100%
A Threesome to Remember - 2 CD's
Since I was a young man I was always curious to find out what it would feel like to get fucked by a hard cock while sucking on a cock. It wasn't until I was 20 that I really started to take the steps to make that fantasy a reality. At 20 I had my first gay experience, I got my cock sucked by one of ... Read full Story
shemale lover 2012-12-17 4,695 Cumshot sucking threesome handjob
95%
Shemale girlfriend
This true life story was posted at our forum by a new member bigbell609. Although it is a pity that he couldn't be with Kristin anymore, his first experience with his TS GF was very remarkable and romantic. Who of us wouldn't love to be in his place... I've been married for a few years now. My wi... Read full Story
shemale lover 2015-04-05 9,651 anal cum fucking
100%
A Shemale Vacation Part 2
We sat there staring despondently at the ground. We had searched through all our bags and pockets and had nothing like the money we needed to pay for the hot sex sessions we had each enjoyed with the hot, hung Dutch whore. The guy, the pimp, who had previously been all smiles and friendly encouragem... Read full Story
shemale lover 2011-09-05 7,122 anal cumming cum swallowing
100%
Shemale Whore and Arab Pimp
Hermaphrodite Whore It had been over a year since Johnny threw that tantrum that ruined me and got him excommunicated from mom. Holding me down when mom walked through the door with her friends, colleagues, whatever and they all gasped and screamed as my big brother finished doing me. We had... Read full Story
shemale lover 2012-07-24 3,035 anal sex Cumshot oral sex hermaphrodite
83%
An Arse To Die For
I'd arrived in Honolulu in the early evening from Sydney and got a cab straight to my brother-in-law's apartment on Kuhio, which he'd lent me for a fortnight while he was up in Europe on business. It's in an ideal situation, a couple of blocks back from all the hotels and Waikiki Beach. I slept l... Read full Story
shemale lover 2012-11-10 4,421 anal tranny oral
100%
Property To Be Pimped
It had been weeks since I'd brought to light my idea of my wife, Suzie, strapping on a big dildo and taking me dressed as Desiree, the Hot to Trot Transvestite. While at first she teased me with possible participation, it never came to be, despite me bringing it up on several occasions. She really d... Read full Story
shemale lover 2013-01-17 7,262 Stockings Crossdresser sucking dildo Interracial
82%
Halloween Double Cross
It all started off so innocently... My wife Jo, tall, slim, blonde, aged 40 with 34DD tits and the sexiest big ass imaginable, works as a doctor. Her hours are long and arduous. She often comes home completely worn out. Only during the holidays does she tend to recover her sparkle. She is gorgeou... Read full Story
ASSEaster5678 2018-10-29 11,303 Shemale Fucks Guy sissy Halloween
100%
HOW ONE PEEPING TOM MORNING TURNED ME INTO A SHEMALE SISSY BITCH
It was while cutting across his back trailer park lawn around 7pm on misty July Saturday evening, when I first discovered that Mr. Parker was really a fag. How else could you describe a man wearing a long blonde wig on his head while below he wore only a large somehow stuffed pink lacey woman's bra ... Read full Story
CDDIXIE4U 2019-01-08 13,892 Teen (18+) Crossdresser Amateur Cumshot Masturbation Blowjob Big Cock Ladyboy Lingerie domination Guy Fucks Shemale Homemade Compilation Vintage cum in mouth
87%
TO BE OR NOT TO BE – PART 1
TO BE OR NOT TO BE – PART 1 by Spanky de Bautumn This is a story about how taking a play to New York City changed people's lives. A transgender coming of age story. I was born Harold Stanley Dayes, not a great name for a kid growing up. I know my parents loved me, but Harold was my mom's dad a... Read full Story
SpankydeBautumn 2021-02-22 3,862 Crossdresser Amateur Group Sex Cumshot Fetish threesome Blowjob Ladyboy Lingerie Shemale and Girl cum in mouth
75%
Shemale Skirt
I have long legs and I love showing them off by wearing skirts. I found a short pink skirt a few weeks ago that I just had to have. I bought the pink skirt and tried it on as soon as I arrived home at my small apartment. I looked at myself in the mirror and realized that the skirt was much shorter t... Read full Story
shemale lover 2015-11-09 5,826 anal shemale oral
100%
Shemale On Webcam Made Me Cum
It wasn't enough for me - regular porn, regular girls... I felt like I was losing it, not having the only thing I really desired: a shemale. But I was new in that world, not knowing where to go, where to look, so I decided it was better to see shemale on webcam first. I searched the internet and ... Read full Story
shemale lover 2015-12-31 3,962 Big Tits Cumshot shemale
50%
Me & Jo Shemale
Yesterday Jo Shemale and I went for on a pussy hunting fall walk. Well, I did, I'm pretty sure Jo Shemale wasn't hunting pussy. It was getting colder, so we had to put on our woolly panties and sweaters. Halfway down the block, we saw the Old Fuck's out in their yard. The Old Fuck's were raking b... Read full Story
shemale lover 2011-08-16 4,605 cock suck shemale
60%
The Ultimate Cock Ball Torture
I miss my cock. Sometimes. I had one once - one of my very own, connected right to me - but now it's gone. Never thought I would miss it. I'm sure you've guessed by now that I am a full transexual. I had the boob job and started hormone treatment years ago and felt much better as a shemale th... Read full Story
shemale lover 2011-11-12 7,092 shemale transformation
50%
Tony's 1st Shemale date
The internet was responsible for Tony finding the best sex he had ever had in and considering he was living in Gosport, Hampshire thought he'd never find his dream shemale date and was able to develop an online friendship with an insatiable, sexy shemale. He had begun an affair with Joslyn about si... Read full Story
shemale lover 2012-04-30 3,180 anal sex Cumshot jacking off
93%
Proud To Be A Sissy Chapter 7
"You're being really dirty little sissy slut today," daddy chuckled and asked, "What's gotten into you?" "Making up for the last few days I guess," I giggled hugging him tightly, "and I missed you too." "I missed my little sissy too." He repl... Read full Story
shemale lover 2012-12-24 7,602 Crossdresser Cumshot Blowjob Big Cock ass fucking
100%
Unconditional Love Chapter 8
After a two' hour nap, Alison and I awoke and the first thing we did was make our way to the bathroom to freshen up. I started up the hot water and climbed into the shower and' once she finished relieving her bladder Allie climbed in with me under the hot water and we embraced each other. We kiss... Read full Story
shemale lover 2013-02-04 6,330 anal sex Cumshot Masturbation Blowjob Guy Fucks Shemale
88%
Never Wanted To Be Your Girlfriend Ch. 01
So here I sit, waiting to hear what will become of me, and I can't help wondering how the hell I got here. I know how it all got started. And it was all Michael's fault -- Michael and I met my first year of high school. We were both the smart nerdy types. And at around 5'6" and just over a 100 po... Read full Story
shemale lover 2014-07-19 7,005 Cumshot suck Blowjob Lingerie facial
50%
My Shemale Sex Adventures
Fresh meat Kevin Judd submits to hot top Korra Del Rio in this sexy Valentines Day special. Sensual domination is Goddess Korra's forte and oh boy does she deliver once she gets her hands on this new submissive slut Kevin. Decked out in seductive, strappy black lingerie, thigh high stockings and hee... Read full Story
KevinRichardJudd 2020-06-16 4,106 Shemale Fucks Guy
77%
Slut indiscretion
At 17, I had reputation among the people in my world. I had sucked more dicks than the average hooker. I had slept with men of every race creed and color. You can even throw in a mentally challenged lad or and autistic child as well. All because I loved getting sex. I think that a penis is the sexi... Read full Story
Regina10 2020-09-16 5,443 Crossdresser Big Tits Cumshot Bareback Blowjob Big Cock Ladyboy Lingerie domination Guy Fucks Shemale Ass to Mouth
50%
I'M A DIRTY WHORE EXPOSED TO PUBLIC HUMILIATION
There are people on porn sites who hunt down people like me and make me a world famous whore. They download all my photos that I publish. Sometimes they add descriptions to photos. They share my photos on all known porn sites, forums, chat rooms. More and more people have my photos. Some people edit... Read full Story
QUEEN HARLOT 2022-02-14 3,061 Big Tits Cumshot Blowjob public humiliation cum in mouth double anal whores humiliated whorehouse degrading degraded public humiliation
50%
SUBMISSA, ADESTRADA E BEM ALIMENTADA POR UM MACHO DOTADO parte 1
SUBMISSA, ADESTRADA E BEM ALIMENTADA POR UM MACHO DOTADO Ha alguns dias atras, quase antes de começar essa coisa toda do Coronavirus e do povo ficar isolado em casa, eu tava voltando pra casa, já umas 11 da noite. Meu onibus, o ultimo, ia demorar ainda pra passar, não tinha ninguem na rua, tudo f... Read full Story
Anymelzinhacd 2023-07-04 853 anal Crossdresser Amateur Cumshot Blowjob Big Cock Lingerie domination sissy femboy Ass to Mouth cum in mouth
100%
About Jack and Diane
Thanksgiving was over the college kids are returning to school and Las Vegas has slowed down from the busy restaurants and overcrowded casinos. It’s the best time of year to see a nice show for less. Jack’s friends had all taken off with families and he had time to think about how lonely he really w... Read full Story
Jon Paul 2023-12-20 6,809 anal Cumshot Bareback Fetish threesome Lingerie Guy Fucks Shemale small cock shemale fucks shemale cum in mouth shemale + shemale
100%
Being Shemale Part II
After sometime the driver left. Night Two I was again ready by 10 Pm as usual wearing make up and sexy night outfit. My push up bra helped my breast look very attractive looked perfect with my slim body I was standing as usual in the balcony around 11 PM and the driver stopped by again.... Read full Story
babydriver 2024-06-04 2,451 Amateur Shemale Fucks Guy Big Cock Asian Ladyboy Lingerie domination small cock big ass Frottage sissy femboy
87%
Amateur Shemale Videos Just Next Door
I rented out a place in this neighborhood not because of the fabulous location but because it was really cheap. It wasn’t what you call a family neighborhood, but nobody was picking on me, at least. My flat didn’t have much of a view. The living room window was facing the building nex... Read full Story
shemale lover 2016-04-12 8,103 Cumshot suck Creampie
100%
Jo, Shemale Goddess! Part 1
Jo plumped the cushion and carefully positioned it until it was precisely at the right angle. Nothing less than perfection would do. Ricki, her friend of twelve years was coming to stay overnight and she would notice if the tiniest thing was out of place. An impatient knock on the door signalled ... Read full Story
shemale lover 2011-09-04 5,473 anal sex sucking shemale
50%
Giving Away Virginia Holton
Today would have to wait, thought Marla Holton as she hurriedly gathered her bag and notebook in preparation for a no-holds-barred departure from her office at Prism Design. As general manager she had the privilege of arriving and leaving at will, though no one could ever fault her for not putting i... Read full Story
shemale lover 2011-10-08 4,598 shemale cum ass fucking
100%
David to Dee Chapter 3
Dee slept for nearly twelve hours following her adventure at the adult book store. While she slept, Gina contacted the nurse that she'd spoken to in the chatrooms by phone, speaking quietly so as not to rouse her exhausted lover. Dee, however, was awake, listening in on Gina's surreptitious plans... Read full Story
shemale lover 2012-07-30 3,609 Cumshot ass fucking oral sex
84%
Alex to Alice Chapter 1
Everything had started off simple enough for Alex. He had met Elena at a bookstore while he was researching for a college paper. She was quite the vision at 29. She stood a respectable 5' 8" with a voluptuous body. While slightly plump, she maintained her hourglass figure and filled out quite n... Read full Story
shemale lover 2012-09-25 4,662 Cumshot domination oral sex
66%
Anal Queen
Amanda fell to her knees in the darkened theater and slowly unzipped my pants. My cock throbbed. As she pulled down my underwear, I felt my manhood spring forth. Amanda took the whole sausage into her warm, soft mouth. I could barely see her face in the darkness, but I could feel her between my l... Read full Story
shemale lover 2012-11-24 6,161 tranny anal sex Cumshot cum swallowing
94%
The Double Sex For Sissy
Jeff Malville awoke slowly, moaning softly. He almost forgot where he was in that moment where sleep and being awake clashed. However, after that split second, it all came rushing back and he moaned in delight. He was a captive on the Double D Ranch, and even though he was considered an employee... Read full Story
shemale lover 2013-04-10 7,673 Creampie threesome blonde redhead domination double penetration