Two Girls on Broadway (1940)

Eddie sells his song to a Broadway producer and also lands a job dancing in the musical. He sends for his dance partner-fiancée Molly who brings her younger sister Pat. Upon seeing Molly and Pat dance, the producer picks Pat for the show and gives Molly a job selling cigarettes. A wealthy friend of the Producer named Chad, also has is eye on Pat. Pat is teamed with Eddie in the specialty number as Kerns and Mahoney. Pat and Eddie soon realize that they are in love and must tell Molly. Pat balks at hurting Molly and goes out with Chad who already has five ex-wives.