Bachelor Flat (1961)

Professor Bruce Patterson is constantly having to fight off the advances of his young female students and is engaged to Helen Bushmill. While Helen goes on vacation, Bruce decides to stay at her apartment but is surprised by the arrival of Libby, Helen's 17-year-old daughter. Having never been told by Helen of this daughter, Bruce assumes she's another student. During her stay, Libby is noticed by an amorous neighbor, Mike.