A girl who receives anal sex willingly, despite feeling somwhat dirty and superfrumpyafterwards.
"Baby, please don't tell your friends. I don't want to be known as up-the-butt girl!!"
by preciouslittlegirl November 14, 2004
n. Word referring to a girl who lets her boyfriend have buttsex with her. She is henceforth known as the "upthebuttgirl" by him and all his friends.
I do NOT want to be the upthebuttgirl.
by danielle July 09, 2005