I don't have anyone to talk to about these sorts of things now, but I've had a weird desire to lately, so I figured I'd just kind of speak into the ether about it.
Years ago, when we were in college, my ex-girlfriend had a friend come to visit from out of town. She was cute, and an all-around fun person. I knew she was kind of wild, but I'd never seen it first-hand before.
One night the three of us decided to sneak into a private pool. We started out just chilling out in the hot tub, as the pool was much too cold at that hour. The girls both had bikinis, but since I wasn't prepared I was wearing boxer briefs under a pair of my girlfriend's shorts … a little weird but it was whatever. Someone, can't remember who anymore, suggested we play truth or dare. It started out with a bunch of truths about sexual habits and the like, until the friend dared my girlfriend to spend the rest of the night topless. Nothing I'd never seen before at that point, but it did act as kind of a turning point of the night. When the friend asked me to choose, I figured I'd go with dare.