Lisa Ann and her boyfriend are going out with another couple, and it's going to be a special girlfriend-swapping night. She's nervous because she's never done any swinging or anything like that, but it's something the two couples have always discussed. She arrives at her friend's boyfriend Mark's home early for the date, and it turns out that both of their other halves are running late due to work. So, Lisa and Mark decide to give their night a test-run, and she pulls out her big tits and sits on his huge hard cock!