No Secret Is Safe
Everybody has its own secret, your best friend might not know but yourself knows it and every detail is just recorded in your brain. Some says that "no secret is hidden" and there is always a place for leakage, this proves true as you tell story to your trusted once in times of temporary and boastfulness.
Maybe you have an idea about it, and you are just currently thinking about your current secret. Yes, your cousin might invite you for drinks of liquor and you might tell him your secret without knowing. Even your cousin might not tell your secret to others, your secret is still revealed and your secret is already not a secret because not only you knows it. So what would be the best thing to do? You must keep a secret-free life by being a good person, it doesn't mean that you should not keep any secret, just avoid bad secrets.