Stands for "Straight-Up Doggy Style;" refers to a sexual position in which a man inserts his penis into a person's anus.
Box 1: Oh my god! You won't believe what happened last night. It was our first time!
Box 2: Gurl, Wha?
1: He wanted to do anal, ON OUR FIRST TIME!
2: You trippin! I don’t believe you! Tell me exactly what happened.
1: Things were goin, bodies thrustin, some suckin and then he’s like “You wanna do it doggy style?” And I’m thinkin UGH NO! You can’t put it there unless you payin!
2: You dumb bitch, doggy style ain’t anal!
1: Yes it is! He wanted anal! Like S.U.D.S. Like Straight Up Doggy Style!
2: You are a retarded hoe! Well what happened after that?
1: He put it in. Duh.