Someones kid brother, whom they refer to as a baby, despite their brothers actual age.
Older Borther: "so hows my baby brother doing?!"

Younger Brother: "Shut up, im 24"
by cornandhash February 1, 2011
Get the Baby Brother mug.
A Tiny person that can be annoying and fun to pick on.
They sometimes hit you with golf clubs in an attempt to ask you to play.
When in a car they scream and have a loud annoying laugh while you watch a movie, which totaly ruins it.
Baby Brothers rarly are good,quiet, can talk, and dont ruin laptops with sticky hands and pop their mother so kindly gave to them.
Baby Brother :Waaaaaah!
Olderbro: In watching a movie,shh!
Babybro:(sees funny part) AHAHAHAHAHAHHEEHEHEHEHEAHEHAHEAHEAHEAHEHUEHEAEHAHEE!!!!!!
Olderbro:screw this, im nnot watching it anymore.
by Rambo1283291048 September 18, 2010
Get the Baby Brother mug.
when your mom has another kid long after she should have stopped because someone forgot to use birth control.
there's me, my sister and my surprise baby brother.
by cheesemac February 18, 2010
Get the surprise baby brother mug.
First the babay shits in the girl's pussy then as he is doing this the girl does an extroadanarily hard position to sock the little boys cock while it's crapping. Then they start rolling on the ground preferrably down a large hill.
:1st person:I Hot Alabama Alligator Baby Brother Blumpy Fuckhouse Pocket'd the shit outa that little baby yesterday.:2nd person:What.
:1st: Yeah Alligator Alabama Baby Brother Blumpkin Fuckhouse Pocket'd the shit outa that little kid.:2nd: Wtf is that? 1st Person: Well it's when (Recites defenition):2nd:I don't think we can see each other any more:1st: Your jealous.
by Justin Carter February 27, 2007
Get the Hot Alabama Alligator Baby Brother Blumpy Fuckhouse Pocket mug.
When two guys receive a blowjob from the same girl. Similar to Eskimo Brothers, but called Baby-Bird Brothers due to the similar action a mother bird uses to feed her young.
Guy 1: "Hey I got a blowjob from Shaylyn."
Guy 2: "No fucking way, me too!"
Random bystander: "Dude, you guys are Baby-Bird Brothers!""
by Randy Rocket April 19, 2018
Get the Baby-Bird Brothers mug.