Small Backed 

Typically performed in crowded bar when trying to get around someone of the opposite sex. The act involves placing your hand on the small of the persons back right above their butt. Typically unneeded contact or mild groping.

Lisa, that guy just small backed me as he was walking by me.

Small Backed by JASONZIMMERMAN September 29, 2014

Snail Backed 

When a girl rides a mans spine and leaves a slime trail.

Kim says "Will you have sex with me Chris?"
Chris replies "No but you can ride my bumpy spine and get yours."
Kim answers "We Snail Backed last week, can't we do so missionary?"

Snail Backed by SWMO GTH May 22, 2015

apple-backed 

The act of shoving an apple down the back of someone's shirt, causing them to have an apple humped back.

Ahh man, I can't believe you just apple-backed me again!

apple-backed by Golden Delicious The Second January 8, 2009

Two-Backed Beast 

The "two-backed beast" is a euphamism for having sex. For some reason, people can't just say "having sex," they have to come up with a clever way to say it.

"Last night I was making the two-backed beast with my boyfriend"

Bumping uglies, knocking boots, burying the salami, etc

Two-Backed Beast by Asty von Ferguson October 6, 2005

double backed monster 

the look and sound of two people having sex that leads others to assume there is a double backed monster in the bed.

i walking in and it looked like there was a double backed monster on her bed.

double backed monster by bnt07 November 22, 2011

bunny backed

bunny backing: (verb) the art of mounting someone's back and penetrating, while thrusting vigorously like a bunny

my wife was vacuuming and i bunny backed her over the couch

bunny backed by jbsbj May 6, 2010

Silver Backed Gorilla

King of the monkeys, no one can be as bigger monkey as this one

Mark Dunne

Silver Backed Gorilla by Anonymous March 13, 2003