Unnecessary doubts

Two boys were playing together. One of them had a collection of marbles. the other had some sweets with him. The first boy told the other boy that he will give him all his marbles in exchange for his sweets . they both agreed.
The first boy kept the biggest and the most beautiful marble aside and gave the rest to the other boy. the other boy gave him all his sweets as he had promised.
That night, the second boy slept peacefully. But the first boy couldn't sleep as he kept wondering if the other boy had hidden some sweets from him the way he had hidden his best marble.

Moral of this story
If you don't give your hundred percent an a relationship, you will always keep doubting if the other person has given his/her hundred percent.