When depressed I became massively obsessed with things. It's like I'd get stuck on something and over think it to the point of it taking over my life. I would google frantically and browse MN, looking for answers. And I'd post on here hoping someone could tell me what I wanted to hear. Admittedly not about other men, more health anxiety stuff but the scenario is similar I feel.
It sounds as though that's what you're doing. The other post Bluntness has referred to and OP has linked to is clearly written by you. All of the phrasing is the same.
Both posts have no real purpose or question. But you seem to want people to say he clearly likes you. People (myself included) have been harsh, likely because this involves others who can be hurt by it.
Honestly, you need to stop posting about this. Stop obsessing about it. And 'ban' yourself from dedicating thought to it. If you feel your mind wandering onto the topic, try and distract yourself.
If you had any interest in stopping this, you telling your DH should have been enough of a nightmare to end it. Or the man's lack of a response. Where is this going to end? What do you want out of this, if not an affair?
If you truly felt embarrassed I think you would be finding it hard to go over and desperately trying to move on. Not writing about it online.
The man's response should be a moot point. You say you know it's wrong, so much so you told your DH and yet you continue to think about it. What's more important? The relationship between you and a man you say you barely see in work, or you and your DH?
I think it's likely this is escapism and you're more obsessed with the fantasy than the reality. I'd have a think about why that might be and focus my energy on that, not anything to do with this bloke. Which could end your marriage and job.