That depends; what confirmation do you have that her affair ended, and/or that there isn't an OM2?
In my sitch, I had really strong intel in place so it was much easier to determine how to play these things. Because my advice to you would be far different if I knew there was nothing fishy going on (which the drive/hotel thing doesn't exactly help!!!).
In general, I'd say make it a fun day for your son either way though.
