So I’m disagreeing with you here. I think she has reason to believe that her husband is cheating on her at that point and that while not ok behavior, listen she starts the series as stressed as she probably thinks she possibly can get, and then as her husband gets meaner, starts treating their kid worse and in some cases abusively (forcing him to drink alcohol), and then starts behaving in textbook cheater fashion. She snaps and cheats with her boss who shows her kindness and desire. I get it. It’s not good, but if a male protagonist behaved that way he’d be seen as complicated.