an erotic act in which a female parts the hairs of the recipient's anus and then places their chin into the anal cavity, making it appear as though they have a french mustache.
"dude did you see that girl i hooked up with last night she was hot"
"she was all right, but didnt it bother you that she had a cleft pallet"
"not really she gave me a french dennis and i couldnt see it, she kinda looked like cap'n crunch"
"hey cecil how was your weekend?"
"you wouldnt belive it, bernice gave me a french dennis, then we watched spanglish while wearing davey crockett hats and 3-D goggles"