rubber ducky on the back 

when a man ejaculates on a woman's back.

Carl: Did you give jackie a ruber ducky on the back last night?
Dan: Oh yes I gave her the bigest rubber ducky on the back last night!

rubber ducky on the back by Thebomb3795 February 7, 2018

Surfing a tsunami on the back of a hippo 

Something completely unbelievable. A comparative phrase when hearing a statement or observing something which is impossible or severely exaggerated.

“I believe that as much as I believe I can surf a tsunami on the back of a hippo!”

“That’s unbelievable! It’s like surfing a tsunami on the back of a hippo!”

Surfing a tsunami on the back of a hippo by Sleepy Unicorn January 23, 2019

Deuce of nods on the back seat 

1920s slang, a fancy way of saying "two days ago"

"a strange broad walked into my office- as strange broads sometimes do. i had seen her before- deuce of nods on the back seat, in O'Ryan's speakeasy."

Deuce of nods on the back seat by hels bels July 21, 2006

Pat on the back 

"Pat on a back"- Backhanded compliment from Patrick. Disingenuous comment made towards people Patrick finds threatening. Unlike compliment "Pat on the back" is not meant to please receiver. "Pat on the back"should always be taken as an insult.

"I Didn't Expect You To Do So Well — Congratulations!, That is such a Pat On The Back Patrick!

Pat on the back by Zong_Zuzia August 18, 2019

Chipmunk on the back Deck

Fetish. When a person gets sexual gratification by feeding small, furry rodents from the rectum or buttocks.

Getting a chipmunk on the back deck always brings a smile to Silver's face!

Chipmunk on the back Deck by Reverend Gonzo August 1, 2018

sunburn on the back of the knees 

only people named abby(abelina) can get sunburned on the back of the knees. if you’re not her you’re out of luck.

Abby: “yeah i got sunburned on the back of my knees”
Person: “is getting sunburn on the back of the knees even a thing?!”
Abby: “wait that’s never happened to you before?”

sunburn on the back of the knees by anhhhh April 15, 2022

Hit it on the back side 

To clean up the mess after a co-worker failed to do a task correctly.

Sandy has trouble counting past 10, so all the orders had to be hit it on the back side after she got done with them.

Hit it on the back side by badger_panther January 26, 2011