It's a Living S01E05 - The Lois Affair

An old high school flame of Lois' shows up at Above The Top, which causes problems for Lois because 1.) Lois and her husband Bill are having a fight and are not speaking to each other at the moment and 2.) the old boyfriend wants to rekindle their romance.  When he wants to have a drink with her after work, she reluctantly accepts the offer and goes to his hotel room in order to tell him that the old romance is long over and that she's married with children.  Meanwhile, Dot and Vicky, overhearing Lois' predicament, follow her to the hotel room in question in order to prevent her from having an affair with her former beau.