v. Ejaculating in a satisfying or otherwise noteworthy manner, especially if an unusually high volume of semen was produced. If the nut was busted under embarrassing and/or hilarious circumstances, chances are it was a mighty fat nut.
I was jerking off in my room, and right as I was about to finish my mom called me down for dinner, and I yelled "coming!", then started laughing really hard at the double-entendre, but the laughter made me double over and I ended up busting a mighty fat nut all over my brand-new polo shirt.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi