From a classic line from the movie "Weird Science". Douchebag Chet (Bill Paxton) checks out crazy hot Lisa (Kelly LeBrock) and says he'd like to "Butter her muffin". This refers to finding her sexually attractive and the desire to have sexual intercourse with her. Lisa then transforms Chet into a pus spewing massive turd-like creature. One of the greatest comeuppances that ever comeuppanced.
Matt: She's not bad.
Erik: Are you kidding!?!?! I've give my left nut to butter her muffin!