butt gust 

when the gluteus maximus expands in such a manner where your pants become undone, or the associated breakage of the lower garment fastening device due to ass expansion.

had to buy new pants today when i butt gusted the button into two pieces.

butt gust by gabmab October 21, 2013

Butt Gusting 

A. When you laugh so hard you fart.

B. When a fart sounds extremely funny.

I had a good Butt Gusting laugh after I let out a squeaker.

Butt Gusting by Jason Henderson Amare April 20, 2013

Butt Guster 

Laughing so hard you fart.

The opposite of a Gut Buster.

Mary: A sandwich walks into the bar, the bartender says, "Sorry, we don't serve food here."

Larry: That was so funny I just let a Butt Guster go!

Butt Guster by Marie1967 September 21, 2011

gusting a butt

1) Laughing so hard at a semi-comical joke that your anus begins to ache.

2) Releasing of severe flatulence to the point where your rectum starts bleeding.

1) "I laughed so hard at Tom's stupid joke that my booty hurts from gusting a butt."

2) "Man, that chili grande did my ass dirty. I think I need to go home and put some Neosporin on my bootyhole cause I just gusted a butt."

gusting a butt by Dr. Nooch June 22, 2012