Any type of glass jar to keep your weed from stinking up your room. Typically made from any type of food jar such as jelly or pickles. You can use a mason jar but using a food item is just more fun.
Friend: Bro wtf are you doing with that jar of pickles?
You: It's my yum yum jar , can't let my old lady smell my loud
You: Don't throw out the jelly ma!
Mom: What the hell do you need it for?
You: Yum Yum jar you wouldn't understand
You: It's my yum yum jar , can't let my old lady smell my loud
You: Don't throw out the jelly ma!
Mom: What the hell do you need it for?
You: Yum Yum jar you wouldn't understand
by Jax182 October 31, 2013

Self explanatory.
Owen: Care for a Chef Hatchet total drama yum yum happy go time fish tail?
Noah: Don't kill him you clown!
Noah: Don't kill him you clown!
by hahahhahnotme October 19, 2023

When you invest in a company and some good news comes out about it, or you make a a lot of money from your position.
"Golden State Warriors is up 367%... yum yum!" - Chamath Palihapitiya (part-owner of Golden State Warriors)
by speakerr January 31, 2022

by Sicktimeslads April 19, 2018

Me: "I need a pinky yum yum in my pinky tum tum."
Her: "That's the last straw. We need to break up."
Her: "That's the last straw. We need to break up."
by big starchos November 19, 2023

A Yum Yum is a sexual act, of when two males stick their fingers in each others rectums & then proceed to sniff their own finger whilst masturbating
Rob: Come here Jonathan you minx, I'm going to give you a right naughty Yum Yum
Jonathan: I can't wait to smell my poo finger, whilst pulling my todger off
Jonathan: I can't wait to smell my poo finger, whilst pulling my todger off
by Yum yum king May 7, 2022

When a guy jizz in your mouth and you pass round the cum equally between your fellow colleagues in the room so everyone has a bit of protein before the big night on the town
Patricia: shall we yum yum this jizz in my mouth
Justine: yes okay
Jeff: yes I'm hungry before the night out. Please save me a piece
Justine: yes okay
Jeff: yes I'm hungry before the night out. Please save me a piece
by Sauly bee July 8, 2020
