My wife's best friend moved to San Francisco a few years ago and met some guy. They have been dating for a while and they recently came to visit for a weekend.
Both my wife and I are 24 and my wife's best friend Laura is 23 and her boyfriend is 22.
They came to our house the Friday night after they arrived. We were all sitting around in the living room talking by the fire and drinking wine when the topic of sex came up.
We quickly learned that for some strange reason Laura's boyfriend wasn't ready to have sex with her and that the situation frustrated Laura. She mentioned that she was forced to satisfy herself whenever she got "in the mood."