I have two daughters, Lizzie (17F) and McKenzie (14F). Their dad and I divorced a few years ago after I discovered he was having an affair. I have primary custody, while he has them every weekend and during the summers.
Lizzie has been dating Jacob (18M) for over a year. Jacob is a kind, respectful young man and frequently visits our house. I’m confident he’ll be valedictorian of their class. A few weeks ago, however, I overheard Lizzie on the phone with someone she was clearly flirting with. Initially, I thought it was Jacob, but she mentioned the name “Brandon.”
A week later, she told me she was heading out to hang with a “friend.” When I looked out the window, I saw her get into a car and greet a guy—Brandon—with a kiss. It wasn’t Jacob.
Despite this, Jacob continued coming over, and Lizzie acted as if nothing had changed between them. They were still holding hands, laughing, and spending time together like a typical couple. Knowing what I did, I felt disgusted by her behavior.
After Jacob left one day, I confronted Lizzie directly. I asked if she was cheating on him. She became defensive, telling me her personal life was none of my business. I told her it absolutely was my business because I raised her better than to deceive and hurt people. Lizzie admitted she was bored with Jacob and found Brandon more appealing, though she wasn’t sure if she wanted a relationship with him or if she was just enjoying the attention.
I told her cheating was unacceptable and that if she wasn’t happy with Jacob, she should end the relationship instead of stringing him along. To hold her accountable, I grounded her and canceled her upcoming senior trip. Lizzie was furious and went to stay with her dad for a few days.
Now her father is upset with me. He says I’m being unreasonable, dismissing her actions as “just a high school thing.” He accused me of projecting bitterness from our divorce and “punishing his daughter.” I told him I’m teaching her about right and wrong and showing her that actions have consequences.
So, AITA?