When you kill someone with a knife and you think it's really really funny.
Arby n the Chief: Episode 11 (part 1 of 2)
Todd: What time is it?
Master Chief: it r tiem 2 dai, tod
Master Chief: tiem 2 dai...
Master Chief: MAI ROFLKNIEF GOEZ SLIEC SLIEC SLIEC SLIEC SLIEC
Master Chief: LOLOLOLOLOLOLOLOLOLOL