look up any word, like spook:
 
1.
1. To insert, place or shove something similarly shaped to or an actual penis into one's mouth. 2. To thrust, spew or release a load of semen with great pressure into someone's mouth.
Example, If you don't shut up, I am going to put this in your mouth!
by Allworld June 18, 2008
 
2.
A combination of "suck my dick" and "in your face" when used to comeback at somebody
Player 1: You suck at basketball

(Player 2 drains shot in his face)

Player 2: In your mouth
by gregb#3 January 10, 2012
 
3.
A phrase commonly used in streetball after making a shot that someone(usually a friend) said you wouldn't make, especially if they also tried to contest the shot.
by saying the term you are basically implying that they should just shut the hell up
opponent:"yo,you no your not gonna make this shot"
*you shoot, and friend tries to contest it*
*ball goes in*
you: "OHHHH IN YOUR MOUTH!!!"
by theG1goodson July 24, 2010
 
4.
abbrev. IYM; oftentimes used to replace "that's what she said". Created by the employees at Legacy Tattoos & Piercing in Beebe, AR.
person 1: "I'm coming."
person 2: "in your mouth (iym)."
by Whoolly Burger November 04, 2010