Secrets (JohnLock)

Sherlock Holmes has a dark dark secret.
Dare he share it with someone he trusts?
Dare he share it with John?
'Got a secret
Can you keep it?
Swear this one you'll save
Better lock it in your pocket
Taking this one to the grave
If I show you then I know you won't tell what I said
Why do you smile like you've been told a secret?
Now you're telling lies 'cause you have sworn to keep it
But no one keeps a secret.....No, No one keeps a secret
Why when do our darkest deeds do we tell?
They burn in our brains, become a living hell
'Cause everybody tells
But two can keep a secret if one of them is dead'