nut-butt contraption

a machine with a metal pipe connecting your wee-wee tip to your rectum. So when the operator of the machine ejaculates, all the semen funnels into his asshole in the hope of making the operator pregnant.

Rick: "Did you know Steve had a baby even though he's a man?"
Nick: "Yeah I heard he used a nut-butt contraption to make that happen."
Rick: "Damn, well how about that."