Sack the back 

To penetrate an anus. Anal sex. Sack to have sex and back as in the behind.

Man that girl looks kinky, i bet she'd let me sack the backQ

Sack the back by ToeKnee September 17, 2005

Spit on the back, Empty the sack

Doing a girl from behind, once you are about to climax pretend to cum by spitting on her back, pull out, then when she turns jizz in her eye.

Little tip...Aim for the middle, you'll both of her eyes.

Spit on the back, empty the sack

She thought I emptied on her back, she wasnt to know it was spit, see turned, then boom!! I emptied my sack in her eyes, the perfect shot.

Spit on the back, Empty the sack by barb heaps December 10, 2006

sack in the back 

The act of a male tucking his penis and balls between his legs (in a Buffalo Bill type style) while turning around, bending over and exposing his ass with bulging sack to passersby.

As my roommate Jim returned from the shower, he tried to gross me out by performing his "sack in the back" routine in my presence.

sack in the back by Ray Boston January 19, 2007

Sack from the back 

When your man ain't acting right...so you grab his nuts and squeeze from the back.

I'm pissed... he deserves the sack from the back.

Sack from the back by Jazmuffin July 7, 2016

Sack in the Back 

When a person places their scrotum between the ass cheeks of another.

Bro 1: Hey bro, can put the sack in the back
Bro 2: I would love your scrote between my cheeks!

Sack in the Back by LlihTter November 6, 2017

Sack Whack on the Back Crack 

The act of thrusting the man junk so far into a woman's (or man's if you are homosexual) anus multiple times that the balls consistently slap against the "host's" butt cheeks making a sound like a great high five.

KirtKanReed: "i am soo hungover bro, i can't remember anything about last night."

ChadKant: "you wouldn't want to."

Zenovia's Playa: " YEAH! BECAUSE CHAD GAVE YOU THE sack whack on the back crack WHILE YOU WERE SHIT FACED DRUNK LAST NIGHT AND PASSED OUT ON THE COUCH!"

Sack Whack on the Back Crack by Zenovia's Playa June 14, 2009

Around the back sack pack 

Another word for a male's jock strap

Did you purchase your around the back sack pack for the upcoming game?

Around the back sack pack by Syelent March 6, 2017