what would you do if you see your boss flirting with your ex girlfriend?

Ex-girlfriend. It means that you are no longer in that special relationship where you can claim to be in a relationship with her. Therefore, it really doesn't matter to me, if that boss of mine is flirting with my ex-girlfriend. What would be interesting to me would be how that ex-girlfriend of mine react and respond to the flirtations of this boss. Anyhow, that's their personal affair and I have more important things to attend to.

That would be pretty awkward, I guess. Probably they'll back bite about the guy. :D

If she is ex let her be ex.

There`s a reason she`s X, l will let him keep her

No I cant. What would that be ?