Deandra "Sweet Dee" Reynolds is Dennis' twin sister and the main bartender at Paddy's.  Sweet Dee was definitely considered a loser in high school thanks in part to her back brace she had to wear back then.  Sweet Dee failed out of U Penn, where she studied psychology.  Now, she's mostly a failed actress and stuck as a bartender with her brother and his friends.

Deandra "Sweet Dee" Reynolds Quotes

It’s really sad, but once your brain’s a piece of shit, it’s always a piece of shit

Dee

Dee: Who slams a door?
Frank: Babies.
Dennis: That guy has some real growing up to do. Have some repect for Christ's sake... I am legend.

It's Always Sunny Quotes

Naked pics online? That's disgusting. On a website? There's so many of them though. Where? Which one?

Mac

No I don't eat dragon, cause, uh, it's not a meal for peasants, it's a meal for kings, and I'm sort of a common man. But they don't eat us, it's a common misconception. They actually eat gold and treasure -- that's why they're always sitting on a pile of it.

Charlie