What is wrong with me?

I honestly think any relationship, even the most wonderful ones, take A LOT of work. First off cut the flirting off right away, although it seems like just flirting and you think it will never go farther, you don't know what will happen "in the moment" i think the feeling you are having for other men is part of being human. Y'all had kids which HAS to be concedered before ANY choices. Just think about what you would be doing to them if you kept up flirting and it became something more. My dad cheated on my mom with a co-worker and i still haven't forgiven him for tearing apart our family. I might be a little harsh, but having lived through such a scenario i can say if you love your kids, don't put them through that crap, it really messes with their emotions and scars them for life. You did have options, but then you had kids. It was your choice so now there are more important things than fantasies of men you work with, i'm not saying you can't think of other men, because that is just natural, but to act on any of those emotions is potentially hurting the thing you love the most, your kids. Good luck