It is the act of inserting your finger in your ass and then inserting it in someone elses ear like a wet willy.
I Brown Willy my pal when im sas
Just like a wet willy, but you stick your finger in your butthole first.
Maze gave Jon a brown willy, after he broke the rules of masturbation night.
when having anal sex doggystyle, you proceed to donkey punch
your partner, then pull your penis out of their ass and stick it in their ear
While having sex with some freak< tony decided to give her a brown willy instead of a dirty sanchez
a cavity search conducted in Canada
at the Quebec customs we were afraid the Frenchies were gonna give us brown willies