What do I do next?

[Telemark]

"I'm not sure what it would do to me psychologically if she was/is with OM."

I'll tell you: it rips your heart out. You feel like dying. You wonder what he has that you don't have. You are in disbelief that your W would freely give herself to another. Your self-esteem and self-respect evaporate. Your imagination runs wild with images of them together.

That's on a good day.

My W admitted her EA to me, but only after I confronted her with evidence of their non-stop texting. She is now living with him. Nothing could have prepared me for this level of pain.

Think about it very carefully before you decide to investigate.