It's a long shot, because I'm guessing she was keeping it a secret and you found out by chance, but marriage counselors aren't just for married people. My bio father and mother saw one after they broke up to better themselves, learn how to get along amicably, and to be better parents to me, especially now that they were single. My mom and step dad saw one too while, and after, they were going through their divorce for the exact same reasons, as well as to deal with anger and resentment issues. Sometimes exes see them to learn how to better communicate and interact with each other. I really hope this is the case, but she still shouldn't have hid it, makes her seem guilty if something more.

god, that is so weird, tragic and funny. at least it's funny from the outside, but it must be horrible for you, if she really wants to get back with her ex. now that I'm thinking about it, there might be a small chance that she wants to work on her general relationship with him, if they have to get along because of other reasons like kids or something.

Have you asked her about it?

Don't walk away. Run away. No matter what her reasoning is, the fact that she would keep something so huge a secret from you is REALLY bad.

At least she's not playing ping pong

Might be her tennis coach.

Wow. What are you going to do? If it was me we would be done.

This is why I'm waiting to meet the right girl on FML!!

At least she's not "seeing" the marriage counsellor..

I wouldn't jump to cheating conclusions. Shes probably got baggage from the relationship (maybe he does too) and shes trying to deal with it.

My guess would be she has issues from her past relationship that she thinks might affect your marriage, she probably doesn't want to make the same mistakes with you so she decided to work through the problems, be happy OP, some other poor dos gets to go to therapy for the benefit of your marriage!

Do they have kids together?