Toasting her buns is when you are having anal sex and you smack the girls ass until it is blood red, hence the "toasting"
Guy 1: Did you Toast her Buns last night?
Guy 2: Totally!!
Guy 1: Nice! How toasted were they?
Guy 2: EXTRA CRISPY!
Guy 2: Totally!!
Guy 1: Nice! How toasted were they?
Guy 2: EXTRA CRISPY!
by BIG TEEZY12345678910 January 19, 2011