Jealousy is both reasonable and belongs to reasonable men, while envy is base and belongs to the base, for the one makes himself get good things by jealousy, while the other does not allow his neighbour to have them through envy.
Hatred, jealousy and excessive attachment cause suffering and agitation. I feel compassion can help us overcome these disturbances and let us return to a calm state of mind. Compassion is not just being kind to your friend. That involves attachment because it is based on expectation. Compassion is when you do something good without any expectations - based on realizing that "the other person is also just like me".
Greed, desire, ambition, jealousy, possessiveness, domination - you have to watch everything. And they are all interconnected, remember. If greed disappears, then anger will disappear. If anger disappears, jealousy will disappear. If jealousy disappears, violence will disappear. If violence disappears, possessiveness will disappear. They are all intertwined. In fact, they are spokes of the same wheel, and the hub that supports them all is the ego. So watch the ways of the ego.
Jealousy in romance is like salt in food. A little can enhance the savor, but too much can spoil the pleasure and, under certain circumstances, can be life-threatening.
Love shouldn't be about jealousy or anything like that. It should be about commitment and being able to trust that person. If you can't have that from the get-go, there's a problem.