Lady Gaga made her acting career the center of the jokes in her Saturday Night Live monologue — roasting her own movie, “Joker 2,” which flopped historically hard in theaters last fall.

“Films such as ‘Joker 2.’ Apparently, people thought it was awesome.” “Joker: Folie à Deux,” starring Lady Gaga and Joaquin Phoenix, was met with not-so-favorable reviews from fans ...