I never snooped, until I realised Karma was hiding things. I have never had an issue with prviacy. He's my husband and I hide nothing from him. He knows all my passwords and knows he can look whenever. My big redflag was when his passwords changed and he had issues with giving me the new ones. To me, that means there was something to hide. Which there was.
Now that everything is in the open I have all his passwords again. He still has privacy triggers from how he was raised, so we agreed I can look whenever I want, I just ask first.
I think you and your hubby need to have a serious talk about the boundries and why they were set. Let him know what you found and why it upset you.
Most likely he doesn't see the boundry as an issue so instead of causing drama, he went ahead and did it and didn't say anything to you.
I don't think what he did was right, but you two need to figure out what to do about it and why it was done.