Not a story about my wife since I'm currently dating another girl, but this is about a girl who is now married but we were FWB for a couple years.
This all started back when I was a sophomore in college. Being an art major you run into a lot of awkward/artsy types of girls who are as diverse as they come in terms of appearance and mentality. It was the start of the semester and I was in studio when this girl started setting up in my space. I struck up a conversation with her and found out she was a Freshman art major. She was actually kind of nerdy looking, 18, white, 5'5",120 ish lbs, shoulder length dark brown hair that she wore up with a septum and gauge piercings. Immediately noticing her piercing, I showed off a few of my tattoos and she was hooked. We talked for a bit and as I was finishing up in studio she invited me to drop by her dorm room later to show me some tattoo designs she was working on.
So it's around 9 pm and I knock on her dorm room and Ileah opens the door and lets me in. As she walked over to her bed I noticed that she must have been wearing the shortest shorts or just underwear with her Atreyu shirt with a pair of socks on. I sit down on the bed and she pulls out a binder and hands it to me. I opened the binder to find a few mediocre designs for tattoos but I pretended like they were awesome. She then asked if I'd be willing to draw one of the designs on her to see how it would look. As I told her that'd be cool, she whipped off her shirt to reveal a nice perky set of B cup breasts with erect pink nipples and a sexy black thong. She laid on her back and asked for me to draw a sparrow getting sucked into a wormhole on her rib cage. After about 20 minutes of work, one thing led to another and she started giving me a bj. I'm laying back on her bed while she's going to town on my cock. After a few minutes I hear the key turn and in walks her roommate. To my surprise Ileah just looks over her shoulder to say "Whatsup!" then continues bobbing up and down on my cock. The roommate just kind of acted like we weren't there and put in some earbuds and listened to music. To my amazement she swallowed my load and asked if I could finish the drawing.
A few days passed before she called me to see if I wanted to join her and a few friends in drinking in their room. It ended up it was just her roommate, a few of her friends and Ileah. We played games and drank for a bit when her roommate left with her friends. Ileah then suggested we play truth or dare and asked me to go first. Trying to impress I obviously said dare. She then proceeds to dare me to quote "fuck her brains out." and tosses me a condom. We proceed to screw for 30 minutes when she then asks for me to put it in her butt. I don't think I've ever met a girl who loved anal more than this girl. She had a perfectly shaven pussy.
The next morning I woke up and turned on her computer and to my surprise I find her status read that she was in a relationship with a guy. I investigated a bit to discover they had been dating at least three years and still sent messages to each others wall that seemed to point to them still being in a relationship. I didn't have too much time to look, but it was obvious. The funny thing was that she kept her status hidden on her wall from other users, so when looking from my account you never even saw a reference to the guy. I thought it was awfully odd, but being a horny college guy I really didn't care since the guy went to college across state and I liked sex with no strings attached.
Ileah proceed to make her booty calls once or twice a day throughout September, she even gave me a few bj's in the back of the studio when we were mostly alone. As I stated before, I don't think I've met a girl who liked it in the butt as much as this girl. At least 25% of the time she asked for it and I was happy to oblige without asking questions about her bf. One booty call she left me in the room while she took a shower before our encounter and asked if I could use her computer. As I opened up facebook I found her profile still signed in, I was faced with a conscious decision on whether to look or just sign out. Obviously I looked and was shocked by what I read. Her BF, I'll call him Kevin, was clueless about his GF cheating on him. The back and forth messages seemed convincing from her on how she loved him and he loved her. To this day I even remember one message sent that day where he said,
Kevin: "Can't wait to visit you this friday, been a long time since we had sex.

"
Ileah: "I know babe, miss you so much, been almost two months since we had sex."
Kevin: "Yeah, how you holding up without it? Tough for me."
Ileah: "Me too. Had to find other ways to get off. lol

"
Kevin: "Like touching yourself?

"
Ileah: "Something like that.

love you soooo much, night!"
I don't know why, but reading that gave me an instant hard on. Now that I look back at it I was an awful person for both reading the messages and knowingly screwing a girl with a bf, but I didn't care. She comes back in after her shower and we screw like wild animals. Friday comes around and I texted Ileah if she wanted to hang out, but said she was too busy working on a paper. I knew it was bs but I let her have her night with Kevin. I kid you not, the next day around 5 pm she texted me a "

" which meant come to her room. Kevin must have been only gone a few hours before she threw me on the bed and rode my dick. As time progressed we did this less often, I chalk it up to just getting to know each other too well, but we had sex off and on for the next two years. That next year Kevin transferred to a college much closer to ours, so it became more difficult for her to play her cheating game. She didn't know that I knew about Kevin, so after a year of our meetings, she finally told me about her bf. I asked her why she was doing this and she just said that her bf didn't fulfill all her needs, but she did love him. Funny enough we screwed right after she told me this. Only fooled around with each other a dozen or so times after this.
We had a couple close calls, but I don't think he ever found out about me. Our FWB situation stopped when he proposed to her in senior year. I also had gotten a full time girlfriend who I deeply loved, so Ileah and I naturally went our separate ways.