What should i do?

I’ve been hanging out with this guy. He is such a great person and cute and i love just being around him. We’ve hooked up a couple of times. But, up until now I didn’t realize I might have feelings for him. So, I literally built up the courage to tell him and before i had the opportunity to say anything, he tells me his ex showed up and says she misses him. So I decided to not say anything cause lol it was definitely not a good time. But anyways, two days ago I stole his jacket and found photobooth pictures of him with another girl (not his ex) in one if the pockets and, to make matters worse, she was wearing the same jacket i had on. Lmao at this point I don’t even think I like him, but I kinda do wanna keep our weird ass relationship the same, cause I really like being his friend at least. I don’t think he realizes I saw the pictures, and I know they’re recent cause he’s been letting his hair grow and it’s long in the pics. Should I be upfront and tell him I saw the pictures accidentally or just not mention it at all?