The act of folding the excess body cleavage of an obese man or woman, typically used for making sweet love to an alternative orafice. Crisco, rendered bacon fat and luke warm butter are all optional.
Leroy: Dude, I went hoggin' on some white bread last night.
Darryl: Did you get the stank?
Leroy: (ashamed look)
Darryl: Don't tell me you went flapjackin' again mothafucka!
Leroy: It wasn't my fault, dat bitch passed out cold so I found a flap and I jacked it!
Darryl: Hell yeah! Jack dat flap negro!
A male with an erection, lies on his back while a second erect male inserts the penis of the first into his anus then lies back. A third male inserts the penis of the second into his anus and lies back forming a stack. A three man stack is known as a short stack, A stack of four or more is known as a full stack. Full stacking has the added benefit of asphyxiating the bottom participants. The flapjacking experience can be enhanced by using maple syrup as lube and having each participant massage the balls of the person above.
Mark, Mike, Jason and Joel were planning a full stack flapjacking session last night but Joel didn't show, so the three had to make do with a short stack.