Getting mad when I ask for phone

So I’m not the person that snoops through your shit. I find that extremely unhealthy in a relationship but my husband just got caught cheating and we’re not at a place where he gets 100% trust right now. Those of you that got caught cheating, when you were trying to rebuild your trust why did you get mad when your spouse asked to see your phone? Were you still hiding something? Was it a kick to your ego? I rarely ever ask. Honestly the last time I asked him was probably over a month ago and I just found out about her 4 months ago. I’m really trying but he’s started doing things that have me wondering so I want to ask to see his phone but i don’t want to make things worse if there isn’t anything to find on there. And I don’t need anyone’s unsolicited advice of “once a cheater always a cheater” or “if you have to go through his phone don’t be with him” if I wanted your advice on whether to stay or not I’d ask. That’s not the question.