He may not be actually having a physical affair, but if he is still talking to the ow, he's probably having an emotional affair. It is my understand that emotional affairs are harder to break off.
I would leave him twirling in the wind. Try to keep the focus on you and what you need to do to keep yourself healthy and busy.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
