I am unmarried. He is married. We work on the same team and have been having an affair for the past year. The affair was consumed at the office (the emotional part) and we has sex occasionally but always outside the office. I kept him away from my personal life and did not get involved in his.
When he wanted to get closer and did out of place things (such as constantly calling me from his vacation with the wife), I pulled back slightly as I saw he started developing feelings and I wanted to cool off things. Unfortunately tension was added when he surprised me with a wonderful gift and did not receive the expected reaction from my side.
As such, about a month ago he started messing around with another coworker. Either because this way he wants to show me it is over from his side as well, or simply because it just came in handy as distraction while I became too complicated to deal with.
I see things progressing by the way them and although I am slightly hurt in my ego (no matter who you are you can't simply ignore the fact that a person who gave you all their attention now gives it to somebody else- all this happening openly, under your eyes), I am more concerned about the fact that this 'let's-see-who-laughs-in-the-end' game will hurt our overall work relationship (an that is a pitty because we do make a great team). How should I go about and be smart on this one?

Just be nice to him like you were before.
I mean if you still wanted him, you'd still have him.

Well most office affairs end up with one person quiting he work and going to work somewhere else.

First he was always giving his real love to his wife, who he went home with every night, so he was always giving his attention to someone else.

And he is having an affair with someone else because he wants to have sex with others and they were available, he may have been cheating with her before but now can do it in the open.

The smart thing to do was not get involved with a married person in the first place. The only thing you can do now is put up with it, or move on with you carrer somewhere else.

If you really wanted to be smart you would stop enabling a married lying azz dog to cheat on his wife. As the ho of a lying azz cheating dog you should have empathy, not jealousy, for his new dumbazz enabler.:eek: