Okay so apparently monday isn't the same as a brother.
CoolKoopaTroopa.
The ones around here will go off if you just say brother without being "ghetto" or some stuff.
They get offended way to easy..
You have some weird black friends then, I'm sure if you walk up to them and call them a "monday" right to their face they wont just laugh and be ok with it.
It depends on your location