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".
Love makes you empty - empty of jealousy, empty of power trips, empty of anger, empty of competitiveness, empty of your ego and all its garbage. But love also makes you full of things which are unknown to you right now; it makes you full of fragrance, full of light, full of joy.
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.
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.