You don't understand men. Work is boring and pursuing women is interesting. Next question?

He MADE you fall in love? There were times in my life when I wished I had that skill! Seriously OP, it’s a two way street, take some responsibility for your feelings… Yes, it’s unfortunate to pursue someone for a relationship and not to stick with the relationship. Maybe he was a jerk, or maybe once he got to actually know OP he didn’t find them as compatible as he thought. It could well be that he was a jerk with a natural salesmanship talent at selling himself, but no long term relationship plans. But regardless of this, we all have a responsibility to: (1) Take a measured approach to someone else’s attention, don’t go overboard immediately. (2) Keep your eyes open for signs that the person you are attracted to is, or is not, really into you. Nothing in life is easy, especially matters of the heart. You have to be reasonably careful to protect yourself from predators of all kinds. But you also have to be reasonably careful to keep your possibilities open for a relationship if you and them are available and compatible. Finally, while we spend much of our life at work (or at school when younger) even a bird knows not to poop in it’s own nest. It’s really better to keep work relationships as cordial but remember coworkers are usually not your friends. If something goes wrong in a relationship (and I think the majority of all relationships usually fail until you find a good match) then you are potentially stuck seeing that reminder every day you work there.

Sounds like a narcissist or sociopath. They only interact if they have something to gain from it, doesn't matter who they hurt in the process.

I agree with the first piece of advice on here, although it’s an essay. It sounds like he was being a bit of a player or teaser, but it also sounds like you might have fallen for him way too easily/quickly depending on how new of a coworker he was. Either way, my advice is that one, you don’t want to be with someone fast or childish anyway, and two, don’t shit where you eat. Never mix business and pleasure, I’ve never heard of a story from around me where it’s ever successfully worked out for anyone. On a final note, it’s okay to feel a little hurt or down though and is understandable—-treat yourself to some nice self care, go out with friends, invest in your health and hobbies, and go on some dates in the near future with people who seem more promising, and it’ll all be behind you before you know it. Also try not to work with or around him if you can.