It's improper for a spouse to cheat on their partner.
Mann and Olga are coworkers who are attracted to one another, but are married to different partners.
Mann wants to bring up the obvious attraction they have for each other.
Mann talks reasonably with Olga, focusing on his marriage.
Mann asks Olga if she wants to have a weekend getaway with him.
They come to an agreement and their marriages remain strong.
Mann becomes emotionally torn between his partner and Olga, painfully.