When someone shoves a bar of metal up someone's ass, typically in a safe BDSM environment. The bar has to be made of metal for it to be considered a monkey bar. Some have also combined two cans of Arizona iced tea to create a monkey bar, but that is a very rare sight.
Those who do a monkey bar are often given names such as "Vlad the Impaler" to hide their identities.
A monkey bar tends to be on the extreme scale of BDSM activities.
Scenario 1:
Trushula: "Hey, did you hear? Vlad the Impaler shoved a steel bar up my ass. I think its called a monkey bar?"
"Yeah, I love it when Vlad does that. I love it when he monkey bars me."
A phenomenon where, when a girl farts while sitting, the air travels forward between the legs, passes over or into the labial area (“monkey” being slang for vulva), and causes a sensation of bubbling or trappedair.
Girl, I farted in History class and it was total monkey bubble. You should’ve seen the condensation on the seat! I hope Tyler didn’t see, heehee!