Dr. Robert Benson, who's new in town, and unmarried. As they are drinking sodas, Barney starts worrying Andy about Ellie and the doctor becoming attracted to one other. Andy finally calls on Ellie one evening and asks...well, orders her to the social with him. She agrees as Dr. Benson arrives and she invites him to go with them. The next day Andy sends Barney to the drugstore to spy on Bob and Ellie and he thinks they are planning their wedding. Andy rushes over to "fight for what's mine" and inadvertently proposes to Ellie. Bob says let's make it a double ceremony. It turns out that Dr. Benson's fiancée is arriving next week. Dr. Benson is never seen or referred to again during the remainder of the series.