Things got off to a weird start when the “Tonight Show” staff surprised Jimmy Fallon for his 40th birthday.

Like, shirtless-Seth-Rogen-and-James-Franco-popping-out-of-a-giant-cake, weird.

Watch Fallon crack up (and say “Oh my God” repeatedly) as he is greeted by the “Pineapple Express” duo before receiving his real gift: a personal performance by the great Stevie Wonder.

“The Tonight Show Starring Jimmy Fallon” airs weeknights at 11:35 p.m. ET on NBC.