In Dungeons and Dragons, a roll that adds to 20 only after adding your modifier. Used to differentiate from a nat 20, as that roll means automatic success, where as a Dirty Twenty may not.
DM: Roll for initiative.
Rogue: Dirty Twenty.
Bard: Nat 20!
DM: Okay, so bard goes first.
Bitch who’s always horny and fantasizing about meeting one of the many men she finds on her books. Big ass fetish with accents and books psychopaths or sociopaths.
“Dude, she just read one of her books and is turning into a dirtyAna...”
The act of inserting a thumb into the anus during intercourse. Inspired by the Happy Day's character,Arthur Fonzerelli, who was fond of giving the thumbs up and uttering "Aaaaaaa(nus)."
"We were doing it doggy style when Christian decided to give me a dirtyfonzie! I felt so violated!!"
A competition in which a man does not shave his beard of cut his hair for 1 year. During said year people who dared the man to enter the contest, provokes him to shave his beard and thus losing the competition.
Seth Rogen's friend in the Movie Knocked Up, dared him to enter A Dirty Man Competition by convincing him if he succeeds his roommates would pay his rent, if he fails which he did he would have to pay everyones rent