I Love You Again is a comedy film released in 1940. It was directed by W.S. Van Dyke and starred William Powell and Myrna Loy; all three were prominently involved in the The Thin Man series. The cast also included Frank McHugh, Edmund Lowe and Carl "Alfalfa" Switzer. Wikipedia
Kay Wilson: Where did you learn to dance like this?
George Carey: By mail.