That wasn't peeking, that was him setting a trap! Fortunately, you acted perfectly and IMHO I would not raise it at all for the rest of the week and even when you leave to go see your parents. Act as if it is something so sad and small that it does not warrant discussion.
I think you H and my W are in the same situation, and I have told my W I do not approve, but nothing more.
I would send you a big chocolate cheesecake, but I think Customs might eat it first. But here's a cyber one to perk up your mood.......yummmm.
Chin up, take the moral high ground and let him crawl back to you.
