Here's what to know about the wild scene, soundtracked by an unexpected Mariah Carey song. Mariah Carey, whose hit song "Always Be My Baby" provides the soundtrack to a wild sex scene starring Joaquin Phoenix and Parker Posey, made a surprise appearance during the premiere. Behind The Scenes Of 'Beau Is Afraid's Shocking Sex Scene With Ari Aster, Joaquin Phoenix, And Parker Posey - Movies Behind The Scenes Of 'Beau Is Afraid's Shocking Sex.