Urban Dictionary: Definitions by The Elias

Incest-in-law

To fuck one's brother-in law or sister-in-law.

Ed: "Wait, Jack fucked his wife Jill's sister?"
Eddie: "Yeah he just committed incest-in-law."

To fuck one's brother-in law or sister-in-law.

Ed: "Wait, Jack fucked his wife Jill's sister?"
Eddie: "Yeah he just committed incest-in-law."

when someone promises his partner he won't ejaculate inside her pussy and he actually does, making a creampie.

OMG!! Bob made a shockpie inside Lana when he promised not to and now lana is pregnant!!