The Goodbye Girl (1977)
A divorced woman and her daughter come home to find that her boyfriend has left for an out of town job with no warning. This has happened before. The second surprise comes in the form of another actor who has sublet the apartment from her boyfriend (who did not mention the pair of females who would be in residence). After some negotiation the two decide to share the apartment even though she has vowed to stay away from actors.
Credit Warner Bros