And if you can get through that first conversation with them, its suddenly easier to not tell them after all.
The longer you have a secret, the more it becomes a part of you. YOU know its true, and eventually you forget you haven't told anyone, because its just something you know then. Like you know that Aunt Mary's dog has brown fur, so this thing becomes part of the fabric of your knowledge.
Thats why its so much easier to slip up later on, because you forgot you didn't tell anyone. Unless, I suppose, your secret is that you are really a (insert other gender here). Then you wuld be hyper aware I guess.
This is (one of the many reasons of course) why I could never be unfaithful in a marriage. I won't say I'm a saint and that I was pure as the driven snow in previous relationships, but I simply don't understand how people could do that in marriage. And to a lesser extent once you start living together. It would consume me! And the lies! The lies that would build on the lies, how do they ever keep track of it all?
Its no wonder that private investigators always say "if you think its going on, it is".
Perhaps my main concern is I'm a pretty hopeless secret keeper. I always want to tell someone. Which is of course how secrets spiral out of control and become common knowledge. One person wants to just tell one other person. Before you know it, everyone knows. I've taken to prefacing a secret divulgence with "can I tell M?" Because chances are if I can't even tell him, its just better not to tell me. Because I won't be able to not tell him, unless the secret directly relates to him, in which case I'll tell someone else!!!