look up any word, like bukkake:
it occurs on a jewish boy's mar bitzvah.
he and his friends, after the bar mitzvah (and the wine...) realize all their gay feelings for eachother and have a huge, gay, drunken, jew, underage orgy.
Larry, why are you walking all funny? come over here and give grandma goldstein and rabbi a hug!

MOOOOOOOM! My ass is sore, after my bar mitzvah, me, chaim, shlomo, and uncle ernie had a butt mitzvah!
by Hryttereanna November 16, 2006
A colonoscopy
I'm over 50 now and my doctor is after me to have my Butt Mitzvah.
by DimeDropped November 18, 2010