In my mind it's a tough call. This is still DBing and while you feel you weren't snooping, you still looked into something that I suspect you already knew would hurt you.
BUT... this is about piecing and both people working together and about transparency and boundaries...
You've put your findings out there and so he now knows... take your time to work through your emotions, even if that means getting away (physically and emotionally) from your H. In your case, just going out for coffee or a ride in the evenings to process.
You need your time to process this and he needs his and you will have another opportunity to discuss the elephant in time.
I just don't think that in the raw emotional times, it is something to get into. Put a pin in it and get on with other parts of piecing that you can handle...
