Phat Back

A Phat Back is a morbidly obese rear end...That's a slight exaggeration.
A person with a big-arse-bootay.

Freddie: "Hey, Mac, You have a Phat Back!"
Mac: "Oh thanks, I got it from my Gran!"
Freddie: "The one who pegged me last night?"
Mac: "Noooo, my gran's the one with one boob - right in the middle,"
Freddie: "Hhahahahahahaha,"
Mac:"She had breast cancer."
Freddie: Smirks, "She could use it to peg me."

Back Porch Tummy Lifter

Method devised to allow the mating process of two super behemoths.

Leroy finally closed the deal with Lefonda by employing the back porch tummy lifter!

dropped his back

A term used when someone has released a pungent fart.

Joe: Look out Dave has just dropped his back, evacuate the room

that shit bite back

to be spicy food; to eat it and the spicyness to "bite back"

Tom: Damn this shit so spicy bruh.

Darius: Yeah I know, that shit bite back.

Story back

When someone changes time by there will in a movie

Ya he used a story back

Back handed scuttle wank

When you reverse the hand when masturbating.

When I masturbate I like to turn my hand around and have a back handed scuttle wank.

the top of my back itches

Your slightly horny

Babe: The top of my back itches..
Boyfriend: Let's go to the bedroom I know your horny...