To maintain the warm of love between couples, they should always have trust with each other; give and take; and cease from strife ASAP.
if they will argue, it is because they want to seek the best solution on their problems and it is not because they want to show who is right or wrong or to hurt the feelings of another.
Apostle Paul taught us that a Christian man must love his wife like his own body. so you will not do harm on your body and you will take care of it well.
To be frank, Both couples should have fear of the Lord in order to maintain the warmness of love and strong bond of their relationship.
So to those singles who read this thread and my message, I advise that you must choose a religious and God fearing as your love partner if you really want TRUE LOVE and TRUE PARTNER IN LIFE.