Saw a girls pic on my bf phone

Hi guys! I just need someone's opinion on this matter that happened last night

So last night my boyfriend and I were in the middle of a cute face time date because of corona and everything was fine and lovely till he flipped his phone camera so that I could see something on his Ipad and the moment I was like "aw look at my pictures as background or in his camera roll.... there was another girl's picture!

I dont know who she was whether she was an instagramer or pornstar or idk who the fuck 🤐

At the moment I couldn't say anything because was talking to his cousin that was in the same room and didn't wanted to cause a scene and be a bitch 😕

But after that I asked him so casually "who was that girl that wasn't me?" And he said what girl and I said the one with long dark hair and big boobs wearing a top!

And he answered "I dont know" and this makes me go nuts because whenever anything remotely annoys him he goes silent 😑

After that I said goodnight and slept and he hasn't messaged me all day nor called...

I'm bumped bc he really cares about me and has helped me through alot i dont think he's cheating on me but I dont want him to save random girls pics...

Am I overreacting or he is just being mean?