When someone with
huge upper-arms flexes, and their bicep then proceeds to hit you in the
face.
See: punch.
Similar to: kneed, elbowed, and head butted.
Lindsey:
Tom! Your muscles are so big,
flex them for me!!
*flexes*
Lindsey: OW, you totally just bicepped me in the face! Thanks for showing me that they were real!