When you get your asshole railed and your lower intestine crammed full of fat, hard cock without the use of lubricant.
I was so horny, not to mention hungry at my Weight Watchers meeting that I went home with the old fat guy and he gave me a hot pork cramwich.
I needed the money so I hooked up with my obese sugar daddy. He gave me the hot pork cramwich as he dripped hot sweat from his forehead all down my ass crack.
A woman's vagina. Typically, you eat out a clamwich. "Clam" comes from the slang that means a vagina, and "wich" comes from "sandwich", which is something you typically eat.
Guy 1: Man, I just LOVE nice, warm, moist clamwiches.
Guy 2: Who doesn't?