Found screenshots of friends in husband’s phone

Hi. This is a throwaway account only for this particular post.

I got married to my long term boyfriend 3 years ago. Everything is going well. Sex is great. No kids.

A couple of days ago, he gave me his phone to send some photos to his family group. While browsing I found a few photos were missing so I went to the recently deleted folder. There was a photo of a girl I didn’t know in very revealing clothes, screenshotted from Instagram. I couldn’t recognise her username, but she seemed quite young, and when I looked her up on Instagram, my husband and her were following each other.

Then later, I checked his screenshots folder, and I found at least 1000 screenshots. All of them except 10 or so were of regular things, news, memes etc. which he sends to me and his friends often. However I found around 10 Instagram screenshots of girls in revealing dresses. And some of them were the girls I knew. One is my friend’s sister. One is the daughter of a family friend. Some I feel like I have seen but can’t pinpoint.

I didn’t know what to do with this information, but yesterday we had a fight on some other issue and he was acting very holier than thou, so I asked him about this. He immediately said he doesn’t know how the photos are in his phone. Then he said maybe he sent these to someone for a photo short inspiration (he is a photographer). But then he just said it’s not a big deal. I asked him outright if he jerks off to these photos and he said he ha porn for that.

Now I am not against porn. I myself watch it sometimes. But I can’t deal with him fantasising about people we know. How can I meet my friend’s sister again and not think about what my husband is thinking?

Is this normal? Is this a ground for separation? It seems extreme to me but I can’t make up my mind. I don’t know what to feel and how serious it is. Please guide.