Little things count BIG time in every relationship. A forgotten promise to call, by itself, won’t destroy a relationship. The cumulative effect of many broken promises will. So pay attention to the little things, don’t rely on the good nature and generous heart of your sweetheart, and avoid doing those things for which you know you’ll need forgiveness. Then, when you do screw up, your sweetheart will be a lot more generous.
Your sweetheart’s forgiveness is a finite resource. Use it sparing.