Friends//lovers

I’ve been friends with a guy for several years. We’ve always had a lot of similar interests, values and almost an unspoken connection. I’ve always viewed it as platonic because he’d been in a long term relationship with someone for most of our friendship. However a few years ago things started going sour with his gf. As an outside observer, it seemed toxic. She seemed very controlling with him and unnecessarily mean. At one point they decided to open up their relationship- I didn’t think anything of him telling this at the time, but his and my relationship subsequently seemed to evolve once that happened. I would noticed him staring at me often… like deep, intense eyes… he suddenly seemed nervous around me and the energy between us just generally felt different. he verbally alluded to our connection as being something more than friendship too. I was weary of this, of course, not wanting to involve myself in such a messy situation/ weird love triangle. Fast forward to present day, he told me last week that him and the girlfriend tried everything to make things work, but are now “just friends”. In the same conversation, he asked if I was dating anyone. I said no, and asked him the same. He said he had been dating casually online, but is t any longer. He just moved back to the same city as me for the indefinite future. I’m not really sure how to proceed. I feel like I’m in a grey area- i feel like I’ve started to develop feelings for him, but I’m not 100% sure about the situation/ where I stand with him. I don’t want to ruin our friendship but I wish I knew how he felt.