Can my relationship be saved?

[a girl]

To answer "how I found out" - his OW's husband contacted me to ask me if he was out of town, because she was "being weird" and saying she had to work late and wouldn't see him or the kids for "a couple days". From there, it was easy to confirm - he just asked her, and she admitted it. He then told me.

I knew it, but having it actually confirmed was somehow worse.

My plan is to not say a word about it. H will know that I'm aware, but we don't need to discuss it.

At this point, I won't see him until it's time to tell our son, and then I plan to go to my "cordial hello/goodbye" that should preclude having to converse with him.

I'm not going to do anything crazy. Peeing on strategic books and clothes he really likes is still and option, though.