Its the ideal reply that overthrows pretty much any insult directed to you. Its a fast, effortless, efficiant, come back.
Bro 1: Hey man you smell like shit
Bro 2: Your mom's tits
Bro 1: Ewww you look like sloppy today
Bro 2: Yeah, so did your mom's tits
Bro 1: Dude why are you talking to Michelle she gets around
Bro 2: So do your mom's tits
Its used as reassurance to make sure your being compleatly honest. If you sware on the boys and a bro finds out that you lied, your not concidered a true friend. One is never supposed to be dishonest while swaring on the boys, its just something you don't do.
bro 1: Did you see my x-girlfriend with Alec last night at that party you went to?
bro 2: Nah man she was solo.
bro 1: On the boys?
bro 2: Alright alright alright I'll tell you verything I saw if you sware on the boys you wont tell Alec.
when one fills a shot glass all the way up to the rim
im not even buzzed yet bro, start filling me up with rim jobs.