is he shy, uninterested, taking it slow or just enjoying my attention?

I work in an office with a man ten years older than me. He is 34, attractive and divorced with a child. He works in a different department doing a similar job so we cross paths but do not work together. He is a supervisor on his team and I am not so our interaction would get us in trouble if we werent careful. He might be shy. Definitely reserved and confident, not an alpha male at all, but he is a rock in his group and very smart. Ive seen him energetic but were both overly cool and a little awkward with eachother. We had about a month of sporadic but intense eye contact without interacting until I saw him at a bar. We saw eachother but otherwise minded our own business until a guy from my group interacted with someone in his. We were both sober and driving. We were introduced and had minimal interaction while the other two men he was with feigned for my attention. I am flattered by having a few admirers at any given time but they never get my attention, im characteristically uninterested but polite. He sat back and watched to the point that my guy friend pointed out that I really had his attention. Their group invited us to another bar and waited for us to leave when they did. We drove separately but when we got to the new bar it was closed. But we bumped into a guy from his group and invited him back to the original bar. He called the one im interested in and he came back too, we sat and talked for 30 min alone but the conversation was very casual, I asked most of the questions. It ended flirtatiously on his part when the bar closed. I was the first to get up but we didnt exchange numbers or make plans, just a see you on monday. Since then we talk awkwardly sometimes and he says hi and looks at me in passing. We shouldnt be interacting at all at work according to the rules. He asked me on friday if I was going 'back' and I said maybe, we talked a little about work and I somewhat awkwardly offered my number. He took it but didnt offer his. We went out and he was there with a bunch of management, people who know we shouldnt be 'talking'. He came anyway and sat by me with my guy friend from work on the other side of me and the 2 of us talked for about 30 min. He was more nervous than me, passive in conversation, bad with eye contact but not distracted, and playing with his glass or keys. He left abruptly to go back to his group but put his hand on my shoulder from behind on his way out to tell me he was leaving and had to get up early. He said it was good to see us and went to shake my hand but accidentally ended up shaking my hand with his right hand and my guy friends with his left, he got embarrassed but ignored my friend. He left quickly, but was back in a few minutes because he forgot to pay for the one beer he had. He came back and sat by me while closing out then left. He hasnt called or texted since I gave him my #. Any ideas about whats going on in his head or what I should do? Im not overly flirty just genuine in convo and eye contact.

Firstly, the number thing is probably him playing is cool. Although it depends on how long ago you gave it to him.

But from what you say he seems interested enough, maybe the age difference is messing with his head a little. Plus he has a kid, so he also has that to factor in. He does seem nervous though, so why not make the first move? From what you've said, it should take a load of his shoulders.