Frosting your cupcake can be defined as when a man shoves his finger into a woman (or man)'s anus, resulting in poop ending up on one's finger. Once the finger is removed, you bake a cupcake and frost it with the unclean finger, and later eating said cupcake.
"Hey Rory, I was totally frosting your cupcake last night"
"Yo, thanks Steve, that was so nice of you to frost my cupcake."
"Anytime, I had fun...frosting your cupcake."
"Word"
"Yo, thanks Steve, that was so nice of you to frost my cupcake."
"Anytime, I had fun...frosting your cupcake."
"Word"
by BigSexy123 October 1, 2013