Stabbing rhinocerous

When a girl with a giant nose is giving you head and her nose keeps stabbing you in the stomach.

Tom: "Dude why is your crotch so bruised?"
Robert: "Its because Betty gave me head last night and it felt like I was being stabbed."
Tom: "Damn that's gotta hurt, I'm pretty sure that's called a Stabbing Rhinocerous."
Robert: "I can see why."