AITA for leaving my husband after discovering he was secretly involved with my cousin?

I (34F) have been married to my husband, Alex (37M), for ten years. We met at university, bonded over photography and travel, and married three years later. We have two children—Sophie (7) and Liam (5). Our life seemed stable, happy, and ordinary. Alex appeared loving, attentive, and trustworthy.

My cousin, Rachel (32F), has been part of my life for as long as I can remember. We grew up close to each other, shared family vacations, and I trusted her completely. She often helped with family events and was very close to my children.

About a year ago, subtle signs appeared. Alex started taking more “business trips” and long hours at work. He became secretive with his phone, taking calls privately and deleting messages. Rachel also began spending more time at our home, sometimes under the guise of helping with the kids.

One evening, I returned home unexpectedly and saw Alex and Rachel in the living room. They were laughing, whispering, and sitting unusually close. My heart sank. I couldn’t believe the betrayal—my husband and my cousin, two people I trusted completely, had been hiding this from me.

Over the next few weeks, I discreetly gathered evidence. I discovered months of flirtatious and intimate messages, secret plans to meet outside the house, and small gifts exchanged between them. Alex had been living a secret emotional and physical relationship with Rachel behind my back.

I confronted Alex immediately. At first, he denied everything, claiming it was innocent joking. But when I showed him the messages, he admitted to the affair. He said it started emotionally but “escalated over time.”

I also confronted Rachel. She admitted she knew he was married but claimed it “just happened.” Her lack of remorse intensified my feelings of betrayal and humiliation.

The emotional toll was devastating. I couldn’t eat, sleep, or focus. Every memory of family vacations, holidays, and quiet nights at home felt tainted. I realized I could no longer trust Alex, and I couldn’t stay in a marriage built on lies and betrayal.

After weeks of reflection and consulting friends and family, I asked Alex to leave and filed for separation. Some friends suggested forgiveness for the sake of the children, while others agreed that betrayal of this magnitude is unforgivable.

Now, months later, I am slowly rebuilding my life with Sophie and Liam, focusing on healing, work, and my children’s emotional well-being. I am learning to trust myself again and creating a life free from deception.

So, AITA for leaving my husband after discovering he was secretly involved with my cousin?