Anthropology Professor Bruce Patterson (Terry Thomas) has the natural British charm that allures women automatically. When his fiancée Helen Bushmill (Celeste Holm) is abroad for an extended time, he has to fight the neighborhood ladies and his students away. Helen has failed to tell him that she has a seventeen year old daughter Libby (Tuesday Weld) who shows up at her mother's home unaware that she in engaged. Bruce's neighbor Mike (Richard Beymer) and his mischievous dachshund also get mixed up in the all the shenanigans happening around the "bachelor flat."