jealousy is a green - eyed monster (shakespeare)
jealousy is the best motor of infidelity (MuDr. plzak)

I see jealousy as a feeling in which I can't accept that I'm not the most important person for her ALL THE TIME. She can't be happy because of other THINGS, she can't be happy because of other PEOPLE, she cant be happy WITHOUT ME, she can't be anything but myself!
Jealousy is so degrading, so sophisticated BAD. And its inseparable part of our life. I think the best thing to do is acknowledge it, make ourselves conscious of it, and then - peacefully observe it, as we would do it with butterfly.