What should I do?

Okay so it's mine and my baby's 3 year anniversary and he fell asleep so I thought I would take a selfie on his phone I went to have a look at the photo and I saw all these other photos of me I thought I'll scroll through and have a look and I saw a photo of some chicks boobs.

Should I ask him about it? or what

Like I always ask if I can go on his phone if mines flat and he always says no and thought he might hiding something but I'm not sure what it was so I let go of it.

That's not the only thing tho.