Hi,
Very good answer from OronD, 2 thumbs up to you. I'd like to add that a healthy love relationship is free from cheating, allows growth in all aspects, there is a satisfying sex relationship. Both couple has a complete bonding with each other. When one partner is hurting, the other feels it too, when one is happy, the other one is happy too.
There is no jealousy because there is complete trust in the other person. The ultimate goal of this couple is to please each other and make each other happy.