Buttcest 

Two or more male family members that have buttsex

Friend: Hey what did you do last night?
RODKING: i had the most amazing buttcest ever with my brother!!!
Friend: Dude, my bro and i have buttcest all the time

Buttcest by RODKING July 10, 2015

buttiest 

a way better adjective the assiest. The region of you body that contains the most butt like qualities.

If you are going to fall on your butt, fall on the buttiest part of it.

buttiest by NdawgVnA October 21, 2009

Buttfest

The yearly mass get together of gay people.

Hey tad, I just got back from Buttfest 2006 and got some greaat assplay accessories

Buttfest by IM SUPER February 19, 2009

buttrest 

To have interest in a nice ass.

i don't know she is, but she got my buttrest peaked!

buttrest by Asheknuckles October 9, 2015

buttlester

A person who molests butts. A person who has an uncontrollable urge to touch, grab, pinch, slap, or caress butts.

Girl #1: did that guy just touch your butt?
Girl #2: yeah, he's a well known buttlester

buttlester by Pitrack01 August 10, 2015

Immaculate Buttception 

Supernaturally having a baby through butt sex.

I ran out of birth control but he was so hot so I only let him do me in the butt but I still got pregnant! It was immaculate buttception!

Immaculate Buttception by JoelskiJizzle April 30, 2020