Premanand Maharaj Ji
What should I do when a relationship has fights and bitterness?
See God in the relationship
No relationship stays strong without bhagwat bhav, the feeling that we act for God. When you act for God, what comes back from the other person is God's arrangement, so there is no reason for anger.
Without bhagwat bhav, no relationship stays strong, because when unfavourable behaviour comes from the other side, your mind will become disheartened.