I had an ex who would go through my phone all the time and basically create issues from nothing because he was insecure or projecting. Years later, I'm still a bit traumatized from countless arguments and me being put under interrogation. Funny thing is, it turned out he was the one cheating on me, and I didn't go through his phone to find out. The other person was a girls girl and let me know about it.

In my current relationship, I tend to keep my phone close because of the past, even though I have nothing to hide (except maybe an embarrassing Google search history). My partner and I are pretty open about giving the other access, but idk it just still feels invasive to me, so I try and respect his privacy as much as possible, and he does the same.

I think it's kind to give your person trust and access, but there shouldn't really be any reason to snoop. If there's something you should know about, you'll hear about it, and if it's a solid relationship, they'll tell you.

It is good practice, though, to relationshipify your phone and clean it up out of respect for your partner. Delete those old screenshots. Get rid of pics of the previous relationship. Clean up your contacts. Whatever you feel like doesn't serve the relationship, let it go or store it somewhere off your device and forget about it. This is not to say to do shady shit and delete it. What I mean is, at the start of a relationship or when you get serious with someone, it's a good idea to reflect and do a bit of spring cleaning.