Jungle Brothers 

When two men have seen each others penises,

"Me and Mark are Jungle Brothers now"
"How come?"
"I saw his penis so I pulled my pants down so he saw my penis too"

Jungle Brothers by Disney Flanell November 15, 2019

Jungle Brothers 

When two men have contacted the same STD from the same sexual partner.

“Yo, I heard you banged Adrian.”
“Yea, what about it?”
“She has Herpes, dude. We’re jungle brothers!”

Jungle Brothers by junglelover August 17, 2021