The violent result of a failed attempt to hold on to your shit for that little bit longer.
1)"did you hear? dave anally erupted on barrys face...."
"ohhh poor him"
2)My Anal Eruption caused continental shift.
A fart that usually ends up with a follow through or if your really, really unfortunate, your ass turns inside out
Tina: "Oh Johnny, give it to me hard!"
Johhny: "Uh uh, yeah, keep it coming..."
Tina: "Ahhh fuck, my ass just erupted!"
Johnny: "Shit, I got your ass all over me!"
Tina: "God those Anal Eruptions ROCK!"