This story is completely true...
My girlfriend, we will call her Marie, and I have been dating for about two years. I know a guy at work who runs a photography company on the side. About a year ago I introduced my girlfriend to him and after some discussion she agreed to pose topless for some pictures for him.
This guy, we will call him Rick, is middle-aged married and has two children. Marie and I are in our early twenties. I had known Rick and his wife we will call her Liz, for some time, Marie had met Rick once or twice before in passing. We agreed on a date and time for the photo shoot, which would happen at Rick's apartment. Marie ad I arrived at Rick's apartment a bit early and Rick and Liz wanted to wait for their children to go to bed before we began the photo shoot so we hung out for about an hour played video games and they served dinner.
While we where hanging out another co-worker showed up, we will call her Cindy, I had no idea she would be there. Cindy had just left the gym and wanted to hang out, Cindy and Rick and I all work together in the same department. Cindy is in her early twenties as well. Cindy had posed topless for Rick, as well as non-topless, a number of times before and was completely comfortable with it.
After the children went to sleep Rick set up his bedroom for the photo shoot and Marie changed into a nightgown, the gown was not very low-cut but it was very short. If she where to bend the right way the bottom of the gown would rise about an inch an reveal the back of her white cotton panties.