Lady Gaga talks about designing her dress, working with creative and talented people, her fiance Michael Polansky being from Minnesota, going to house party with him there, being proposed to while rock climbing, what the music at her wedding might be like, playing Harley Quinn in Joker: Folie a Deux, singing in a way that was unnatural to her, acting with Joaquin Phoenix, and performing all the songs from her new album Harlequin at a secret show in LA. Watch 'Jimmy Kimmel Live!' WEEKNIGHTS 11:35/10:35c on ABC. Stream on Hulu.