My husband’s been cheating on me with his ex for years

Ever since we started dating, I knew that he loved both of us at the same time, and I knew I was the one who came after. He chose me even though his ex begged him to stay.

A few months later, I found out that she was pregnant and chose to have the baby even after my husband left her. Despite that, I chose to forgive and stay with him. I let him settle the situation with his ex.

I believe that he truly loved me. My pictures are all over his social media, so why is he still cheating on me with her? He even hides from her the fact that we’re married.

It would be okay if he only has a co-parenting relationship with her, but he has been sleeping with her once or twice a month over the past four years.

He even asked to meet her a week before our wedding and asked to sleep with her. During New Year’s Eve, he wanted to meet her but she refused. It’s been a year since then.

Even though he was refused, my husband still texts and calls his ex, begging for a meeting. According to their messages, they have already broken up and only talk to each other regarding matters with their child.

I don’t understand why men can willingly betray the person they love because of sex?

My husband and I have sex regularly; he’s always been gentle and tells me he loves me. Is it normal for men to have extramarital sex?

What should I do now?