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.
Although we are all the same in not wanting problems and wanting a peaceful life, we tend to create a lot of problems for ourselves. Encountering those problems, anger develops and overwhelms our mind, which leads to violence. A good way to counter this and to work for a more peaceful world is to develop concern for others. Then our anger, jealousy and other destructive emotions will naturally weaken and diminish.
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.
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".