Your uncle called said bring a friend, its fun to screw and to pretend

The story:

I had always thought he was singing about his perverted uncle who wanted to sleep with his friends. I had my head phones on in an elevator and the song came on i was singing it softly but could still be heard. My friends were just staring at me and started laughing. After making fun of me for a while they clued me in to what the real lines were