Sling back

When you pull the pussy tongue with your mouth and pops back to place.

Boy I sucked that pussy and the sling back was wow

Back of the steel drums

Anal, especially in a band room or with instruments

"Bro, Sharon let me in the back of the steel drums last night!"

Incest (The I Do It Myself Back Smacks): The First Juvenile Release

What I call homo-sapiens who are addicted to perianal abscesses.

Person 1: Are you addicted to perianal abscesses?
Person 2: Yes.
Person 1: Incest (The I Do It Myself Back Smacks): The First Juvenile Release

back door santa claus

next to impossible spare while playing video bowling

7-10 split and as the ball careens down the lane, in order to encourage the ball to get the spare you say "back door santa claus"

blow his back out

When a gay guy fucks another guy too hard and he can’t walk for a few days

Guy 1: dude I’m gonna blow his back out

Guy 2: no way man

To the end of the Multiverse and back

Going beyond just the universe to profess whatever it is you want to convey to someone

I love you to the end of the multiverse and back. Or I hate you to end of the multiverse and back. Your choice

Throwing the catfish back

When you invent a whole alter ego to pretend to become romantically involved with so that an an ex or a stalker or anyone who is being generally pushy and invasive in your life will waste time investigating a non-existent person and leave you alone for a while.

I'm throwing the catfish back and inventing a fake new love interest to get my ex off my back and spin his wheels for once for a while.