Co worker, strange motives??

I don't really know where to start...Well I have been working with a married colleague for about two years now, and the last month or so I have noticed that he has been more and more around wherever I'm working and talking to me. If I'm doing something, he'll come over and be in the same area where I am and start talking to me. Whenever I pass him, he says my name and talks to me, and a lot of times he will "accidentally" brush up against me (coincidence???) He is always super friendly to me, even when you can tell he is in a bad mood, and always gets upset when work is done for the day and I have to go home ("why are you leaving? can't you stay and help me with something? let's work on this project together") He is always willing to drop whatever he is doing if I need help doing something as well. I don't get it, though. He never talks about his wife, never wears a wedding ring and he even called his wife his "girlfriend" instead... which frankly, I find strange... anyways, I don't know if this matters or not, but whenever he starts singing at work, he always puts my name in love songs? And he will kind of just stand there are glance and stare at me. Wtf is up with this guy? I would never be a homewrecker but I am just very curious, as he's a really nice guy and I wouldn't want to ruin a good friend and work relationship we have. Should I try to avoid him? I don't want to develop serious romantic feelings that's for sure!

Keep an arms distance from your married work colleague. His actions are telling you that he's not happily married and he doesn't respect his spouse. Sure, you can have a good working relationship but ask yourself what sort of a friend he is. You well know what's going on if you can state that you're no home wrecker but you need to understand that while this guy is looking for something else outside of his marriage and trying to involve you, you're basically heading straight into a no win situation. If you feel this guy IS a really nice guy and a good friend, then you should be able to tell him direct where he stands with you without any fear or recriminations. If his marriage is failing then it's his business to sort and you need to tell him to do just that. It's not so much about you ruining a good relationship with him, it's about him already tainting your work relationship by his very actions.

How would you feel about the guy if you didn't know he was married? Do you think you could care for him? If you do, maybe you can find a way to deal with the marriage.