F is for Fart (2012)

School girl Yoshie is obsessed with her teacher Miss Yumi. One day while outside, a deadly gas breaks forth from the ground and kills anyone who inhales it. Yoshie and Yumi escape into a building where the former wishes to smell the latter's farts instead of the gas. Yumi farts in Yoshie's face and she is transported to a gas-filled dimension where she and Yumi make out.

Unfortunately the movie F is for Fart is not yet available on HBO Max.