Duff

DUFF - Designated Ugly Fat Friend.

Doesnt have to be fat or ugly. The weak link in the group of girls. The least attractive but it the most approachable. Use her to speak to the girl in group you want to score with.

"Damn Cindy so hot, how do i even get a chance to speak to her?"

" its simple my friend, get to know her DUFF Sarah & youre in"