When the joker thinks his/her own joke is hilarious, but no one else does. He/she laughs, and everyone else laughs because it is funny that he/she thinks he/she is funny.
Sam: "I'm very punny, get it, punny? Ha ha ha ha ha ha!"
Josh & Mike: "Umm."
Josh & Mike: "haha!"
Josh to Mike: "dude that was a total dads joke"