You're being set-up. This is what's going to happen...
She's going to use the MC as a way to blame you or to come up for reasons why she's been unhappy for years. Some will be true, some not. Many people here haven't been to MC because the timing wasn't right.
It doesn't sound like the time is right for your sitch either. MC will not work unless the OM is out of the picture. MC works when both parties at least have an interest in saving the marriage, no matter how small. Your W didn't even invite you to her TKD event. That's not the sign of a woman who is open to R.
It's the sign of a woman who is keeping her options open. She has you for a paycheck and the OM for her emotions. Who do you think is she more in to?
If at the very least, be sure that the MC you go to is very pro-marriage. That is a must! Your W will spew all sorts of things that would make your head spin. Be sure the MC you choose keeps things in perspective and in line.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.