Girl: OMGZZZZZ YOLO YOLO YOLO LOLOLOL xD xD :p
Dude: Fuck you.
Stands for, "You Only Live Once."
"You stole a car???"
"Yeah. Whatever; YOLO."
"I dropped out of school and my parents won't let me live with them."
"Oh well. YOLO it."
"I say YOLO, because YOLO!"