1. (n) A fetishistic oral consumer of bung butter, the mixture of lubricant and Santorum which is the result of anal sex. 2. (n) A much more creative pejorative term which may be substituted for the more common "cocksucker" or "asshole".
smb: if you wait a few years i can potentially hire you as a houseboy or bangbutler
ksi: hhahahaaa I'd be a very sad bangbutler. You'd do much better with a young one.