The act of sitting on an open bottle of tequila and doing a hand stand. Gravity will empty the bottle into your anus, causing an alcohol-induced blindness that will send you into a furious fiesta. Ole!
Tom: Hey PJ, two words: Tijuana Takedown.
Tom: let's get ass-drunk
PJ: cool, I'm down do be a drunk ass tonight
Tom: nah man, it's where you get drunk via your ass. Like a tequila handstand.
PJ: sounds dangerous.
Tom: fuck ya it is. Let's sit on some bottles!
PJ: no fiesta.
To take a moderate dose of cocaine ("bump") off the head of an erect penis ("mushroom").
Tom: Dude, you see that guys' boner?
PJ: No, Tom give up the dream
Tom: Imma go over to him and ask to give him a mushroom bump
PJ: what's a mushroom bump?
Tom: it's where you take a bump of cocaine off the head of another man's boner!