Upside-down b 

Upside down b - which if you look at it as a lower case, means p, or methamphetamine. This is a common term used in New Zealand, made famous by Bro'Town.
The letter p is likely to be derived from the main ingredient in methamphetamine, pseudoephedrine.

Eh bro'! I can't believe youse got hooked on upside-down b!

Upside-down b by Rebelmonkeys October 2, 2006

Upside Down Buffalo Jerk 

When a guy is standing on his head and the girl is giving him a hand/blow job and as he is about to cum she sticks her finger in his butthole and jerks him off the floor. (Animal noises optional)

I am working out so much now that I can upside down buffalo jerk my boyfriend three inches off the ground!

Upside Down Buffalo Jerk by Kristashia February 7, 2009

Upside Down Brown Cake 

The act of a man having sex with a woman while she is performing a headstand. During this position his penis is inserted into her anus while the man defecates into her vagina.

This is difficult and will most likely cause his feces to enter the vagina while simultaneously dripping down her body and face like chocolate on a cake.

Last night at the orgy I saw someone doing the Upside Down Brown Cake so I played with myself performing a Sleeper Hold because it was so hot.

Upside Down Brown Cake by FattUnit April 29, 2011

Upside Down Baseball Bat 

When you have a guy skeet in ur ass and then a girl with a big black dildo fucks you in your asshole and then beats you off and pulls out of your sss as you come making everything leak out of your ass and dick

Me, daryl and debbie had an upside down baseball bat last night and it was the best anal explosion I have ever had

Upside Down Baseball Bat by Big cock carl June 14, 2018

Upside down bowling pin penis 

A penis that is shaped like an upside down bowling pin with the base being thin and the head being extremely girthy.

Robyn wanted the credit she felt she deserved..... after all..... she was the one who sucked off the man with the upside down bowling pin penis

Upside down bowling pin penis by LemmeF1ndOut November 27, 2021

Upside Down Boner 

When an erection is restricted from achieving the 45 degree upright angle and points south instead.

some bitch at da club wuz backin up on my shit and my belt gave me an upside down boner.

Upside Down Boner by DFA, bitches October 8, 2011

Upside down blumpkin 

69ing while taking a dump.

It felt so good getting an upside down blumpkin yesterday man.

Upside down blumpkin by MissBoleyn January 10, 2012