**Let me preface this by saying that I'm not going to (or looking for an excuse to) engage in a relationship that is going to wreck someone's home life. Also sorry for the novel, and thanks so much for reading!

Okay. I'm 30-something, single, and okay with that. I'm not saying I wouldn't date if someone awesome came along, it's just that no one more awesome than the independent life I currently have has. I have been working for the past 4 years on obtaining a degree which will allow me to advance in my current career, so this has kept me from dating seriously as well. I work in a high stress professional environment--professional in what we do, not necessarily how we act (we joke around a lot, we have "gallows" humor; it's all part of the work culture). For the past three years, I've had a work friendship with a man ("B") with whom I have a lot of chemistry. It's acknowledged on both sides, no question. Chemistry in that we have a lot of silly little things in common that most people our age do not, not heady sexual chemistry (not that's acknowledged, anyway). We're both huge geeks, let's just leave it at that. And we enjoy talking to each other about our incredibly geeky interests.

Problem on my side is that from day one I have had a huge attraction to him: to be blunt, he's exactly what I want in a partner. Given this, knowing that he's happily married with children has caused me to tread very lightly. I don't outright flirt, but I do talk to him. As I said, I enjoy talking to him, as do most of our coworkers; he's one of everyone's favorites. Problem on B's side is that I think he is outright flirting. When we first started really getting to know one another, he used to like and comment on my Facebook posts fairly frequently. Not terribly flirtatious things, but when I'm the only female co-worker he's showing attention to on FB (actually, the only coworker period), if I were his wife, that would bother me. I no longer have a FB, and anyway the likes and comments abruptly ended about 3 months after they started. Now it's things like, idk, when I squeeze past him, he'll put his hands on my hips to kind of guide me as I go by, you know? Just a lot of random comments and little physical things that all kind of add up. Then the other day, I was having a rotten shift, and he hugged me. Not a light, one-armed side squeeze...this was a full-on bear hug that lingered. And since he's about 4 inches taller than me, it was hard for my head not to get tucked under his chin, my face buried in his neck. It was more action than I've had in a long time, tbh. I think somewhere in the time I was being squeezed by B, it clicked that I had probably crossed some kind of line somewhere. I just didn't know how or where (having a crush does not an affair make, imo). To be clear, B's actions are not the miscreant kind of flirting that you'd see at the bar on a Saturday night. It's more playful, less overtly sexual. However, my spidey sense is tingling. I guess I'm afraid that, since his attention has only increased over the years, it will continue to do so. And then what?

I've heard that if a man was a flirt before he was married, he'll still flirt and that it's usually harmless. They like the thrill of the chase but love to go home to the one that they finally caught--their wife. Okay, fine. And I can deal with that. I'd be lying if I said I didn't enjoy his attention. However, aside from the obvious factor of his unavailability, I am hopefully about to advance within this organization to a position which I will need to commit at least 5 years. He's in a position that's not really above me--I'm not his subordinate, our jobs would be (more) symbiotic--but let's just say it would not benefit me for us to be connected in any kind of scandalous way. It wouldn't be good for him either but I would definitely be the losing party in that situation.

So what say you, forum? It feels like a sticky situation. I want to remain friends with this person. He's a lot of fun. But I don't want to find myself in over my head. Do you think his flirting is harmless, or should I be concerned and pull away?

Or am I way overthinking this (which I do everything anyway)? I know you don't know us, but give it your best shot.

TL;DR: My married coworker/friend of three years whom I have a crush on is a playful flirt, but is highly attentive and has advanced to a more physical kind of flirtation lately. What are your opinions on his motives--innocent or not so much?

Thanks in advance.