This.

In a past relationship I was cheated on.

Did I want to know about the other woman?

Hell no. She didn't factor into the situation at all. I didn't know her, she didn't cheat on me, and I didn't want or need an explanation from her. If it hadn't have been her, it would've been someone else.

I wanted to know what HE was thinking, why he did it.

I wanted to know why our relationship wasn't enough, why I wasn't enough, what it was he wanted so badly that I couldn't give him.

There are many reasons why people cheat, but it comes down to one thing, really.

A person cheats because they aren't happy with their current situation, i.e., their partner.

And this article explains that so well.

My ex bf eventually left that woman and ended up marrying someone in his firm and they now have a baby. He is happy, and that's a good thing.

So am I.