I am your girlfriend's friend and you agreed to be the sperm donor for my wife and I! I wanted a hand in getting her pregnant, so the arrangement is that I will be the one to make you cum. I am jerking you off and you are under the impression your girlfriend is using a fuck machine behind you. She starts moaning and I tell you that I actually invited a friend over. He is fucking your girlfriend in the ass right behind you while I jerk you off! Can you hear her cumming over and over again? Don't look or I will stop stroking. I describe what is going on behind you, all you can hear is her moaning in pleasure. I start off in a dress but strip to bra and panties a few mins in, and strip naked the last couple of mins. I tell you when to cum, your gf still moaning behind you while she sucks my friend's big cock!