I was the guy that was blowing ol' girl's back out once. Not as great as it's cracked up to be. In my case (and maybe a bunch of others), she was fukking with me because she was frustrated with the guy she was supposedly working it out with, and was messing with me to blow off steam. She and I were sort've friends, so I got to hear a TON about how frustrated she was with him before she would ask to get busy.
Semi related, I was also once the friend a girl told her man not to worry about. I was young as shyt, so it was actually fun since he was a cornball who didn't like me from the moment the three of us interacted for the first time, even though I wasn't really planning on making a move.