How do I broach this?

[Sandybeachbums]

I’ve met a wonderful man and we’ve been dating for the past few weeks. Everything is going great. No intimacy yet as I want to take things slowly after being in previous bad relationships where I’ve been lied to and cheated on.
We’re both divorced. I’ve been single for a few years now and he told me he’s not had a relationship for roughly the same period.
I went to his home at the weekend for the first time and there was a photograph of him with a stunningly beautiful woman on display.
I asked who it was and he replied ‘someone I was seeing’. No name (we’ve talked about exes and he’s been forthcoming with his exes names etc but not this one). I don’t know how long ago it was as he just shut the conversation down.
It’s rattled me. I know we’re only a few weeks in and have yet to have the chat but he’s assured me he’s not dating/seeing anyone else but the photo has really upset me.
What should I do? Say something? Say nothing? Walk away?

Thanks all for your replies.

@Watchkeys I’m going to have to ask him face to face and take it from there as my imagination is in overdrive.

The photo does seem something more than someone he was just seeing, anyhow, it could be he forgot to take it down before you came round and feels awkward about talking about it, not sure it would be a dealbreaker just yet but you're definitely doing the right thing taking it slow and taking notice, more importantly take notice of how he treats you.

My ex (when I was young adult have been with DH since I was 20) kept my pictures up for at least six months after we split. Not sure why.

I kept his up for about the same and honestly I don't know why. When now DH asked me who it was I lied and said it was my best friend. Obvs he now knows but he never asked me about it!

He wanted you to see that picture and he wanted you to feel mystified and threatened by it. He is a manipulator. Be careful.