"Busting one"is busting one of your testes, another word for ejaculation. "Fat" is simply an emphasis for the amount of sperm ejected from the penis, in this case there's a lot of, and you better hope that thot enjoys your white warm creamy testicular fluids.
*Girl kneels down*
*sucks man's Penis*
*Man's about to climax*

Jerry: I'm going to be busting a fat one on your face
*Jerry pulls out of women's mouth and aims the penis towards her face*
*Jerry shoots*
*Jerry satisfyingly watches the sperm trickle down her face*
by Woketh Loops August 4, 2018
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Something that should not even be thought about during the month of November
(During the month of November )
Rahul:yo I just bust a fat one
Ahmed:*shoots him*
by Shut up blud November 3, 2019
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