Rump Bump 

When two people bump butts, sans trousers.

Only real best friends Rump Bump

Rump Bump by thebattlefish August 25, 2011

Rump bump 

Chronic acne on ones ass

I tried to clap that, but got too disgusted by her rump bumps

Rump bump by Mliv March 16, 2020

rump bump 

rump bump means that when a man grabs a woman/man by his/her hips and shoves his hard erect penis into her ass crack, while in the process of pulling his/her pants down. then, they shove the person on the ground, get on top of the person and rides them like a pony, then you go 69 on their ass

damn bitch, i had sonia over last night and i tried to rump bump her ass but it was too flat and nasty, and she was terrible.

damn hoe, i had m&b in bed last night, they were the best rump bumpers i know.

rump bump by Marissa(: June 13, 2008

bump a rump 

To do it up the bum. Aka anal sex.

P1: "Yo bro I totally hooked up with dat chick last night."
P2: "Awe man, you bump a rump?"
P1: "Straight up."

bump a rump by kiTTy♥ June 11, 2009

Rumpbump 

The act of sniffing cocaine, or other powder drug off an ass. "Usually a female stripper or prostitute"

She'lol let you take a rumpbump if you give her one too.

Rumpbump by Comeagain,saidvirginmary April 15, 2018