AITA for going through it without asking?

AITA for going through without asking? I 16F went through my boyfriends account 15M. So today like maybe a few minutes I was like, I could go through his account because i was getting emails, because his account is currently set up on my account bc his phone is broken, and I feel really bad for doing it. But he never really talks about reddit or mentions that he doesn't use it? But i was checking his subreddits, that hes in and there's a few nsfw ones. and I also went through achievements and saw one which was gotten when we were like 4-5 months in our relationship, it really upset me even though its my fault for snooping and not asking? Am i wrong for being upset when i snooped?? 😥