Okay.. that sucks the big one. Knowing the 'truth' shreds a swath through the heart. Sending hugs.. and what I found helpful in my case..
I don't hold on to someone who doesn't want to be with me..
then changed it to..
I don't hold on to someone who doesn't treasure being with me.
Spouse wasn't doing anything different (lies, involvement, behavior, joint checking account with her, etc). My awareness changed how I felt, how much more it hurt.
Pain is inevitable, suffering is optional.
Reading 'Not Just Friends' was a life saver, especially the part about forgiveness. Bitterness masks anger which is unresolved pain and hurt. Forgiveness is a gift you give yourself. Feel your emotions, then send him blessings. It relieves the anger, puts you in a better place and drops the rope. It's terrible at first.. but worth it over time.
If it feels right, a positive thing to do, the answer is yes. If it feels wrong, the answer is no. If you waffle or can't decide, the answer is no.
