Boyfriend freaks out when I touch his phone

My boyfriend of 4 years has always been very secretive about his iphone. A few days ago we were hanging out, we got lost and so we used his phone for google maps. He was putting in the address wrong so I said "give it to me I'll do it"... immediately he freaks out saying NO. I found it bizarre but I let him figure it out, 5 min later he has no idea what he's doing plus we're in a sketchy area so I demand to do it. I take his phone and he completely freaks out! I couldn't even open google maps without him snatching away his phone from me.

Btw the few seconds I did have his phone in my hand, he demanded to see what I was doing plus when I was scrolling through his iphone I accidentally opened the photo app, immediately closed it and proceeded to look for the google maps app (that's when he freaked out and yelled)

I got home and haven't texted him since because I don't even know what to say or how to handle this. I feel like he is hiding something because of how he reacted to me having his phone. I'm just very confused and need advice