I would be crushed if I found out my husband was cheating on
me. That would include seeing (dating) another woman.

You don't have to be having sex to be cheating.

I'm seeing this from the side of the wife.

Also, it's no great shakes being the "other woman" either.
Unless he decides to divorce his wife he can never really be
yours, and if he does, do you want to be responsible for that ?

I say, leave it alone. It will only lead to heartache for you !!!