Usually a term for exasperation, interchangeable for Fuck me in the ass, I hate my life, or fuck everything.
Guy on headset: "I'm about to get 40 to 1 kills!"
*Guy gets shot*
Guy on headset: "Well fuck my ass!"
A shitty way to prevent embarrassment from telling a story horribly and getting a poor reaction. Usually aggravates the hell out of me.
"And then he goes to motorboat her-Ya know what, you should've been there!"