look up any word, like cunt:
Any type of activity involving fat bitches and lunchboxes.

See related words: "Fat Eating", "Fat Driving", "Fat Eating"
Stoner 1: Where is Fatboy?
Stoner 2: Probably Fat Fuckin
Stoner 3: Black Ass
Stoner 4: Lunchbox is all about that Fat Fuckin.
by Weed Man April 01, 2004
An analogous act to a titfuck, performed by a guy on an obese partner, using rolls of fat instead of breasts for stimulation.

Also as a verb, fatfuck, not to be confused with fat fuck (derog.).
My girlfriend is so fat, dude. When I fatfuck her, my dick disappears!
by luvthabiggest May 25, 2005