A fat guy or girl's fake life they brag about online
Guy online: Oh yeah, my girlfriend has DDDs, we had a threesome with Megan Fox the other day.
Other guy online: Dude, you're like 400 pounds in real life, stop talking about your fatasy
(Noun) - An exceptionally large girl with an excessive amount of junk in her trunk that you realize you want to hide your bologna in her. Grab your spear and your galoshes, cause your goin whalin'!
1: DAAAYYYYAAAM THAT GIRL IS HUUUUGE.
2: I know, she's my fatasy.