When people date, they progress from the getting-to-know-each-other stage into being able to understand each other. They build trust along the way, and this helps their love and affection for each other deepen. When they have built enough trust, they often share their most secret thoughts and feelings about certain subjects. Secrets, those thoughts and fantasies shared with no others, are when the relationship has truly become a bond between them.
Sharing secrets and fantasies with a partner only occurs when both people trust each other, but sometimes one partner is more trustworthy. It takes a great deal out of a personal relationship when secrets between couples are shared with others outside the relationship. When a person breaks the confidence of their partner this way, the relationship might never recover. Many people choose to keep their own secrets rather than take a chance that their partner is not as devoted as they seem.