If you aren't the Secret Keeper, you can't share the secret. You don't die, you just can't do it.
In order to reveal Grimmauld Place to Harry, they had to use a paper that was written by Dumbledore himself (the Secret Keeper), because they couldn't share the secret, even if they knew it.
Harry looked down at the piece of paper. The narrow handwriting was
vaguely familiar. It said: The Headquarters of the Order of the
Phoenix may be found at number twelve, Grimmauld Place, London.
Rowling, J.K.. Harry Potter and the Order of the Phoenix (p. 54).
Pottermore Publishing. Edición de Kindle.
At the beginning of Harry Potter and the Half Blood Prince, Dumbledore still was the Secret Keeper, thus, Snape couldn't reveal the location of Grimauld Place.
According to this article:
The Fidelius Charm is extremely ancient and still used to this day. It involves the concealment of information inside a living person. The chosen person, or Secret Keeper, is the only person who is thenceforth capable of revealing the protected information to others, however many previously knew it. If the Secret Keeper shares the hidden information, the person to whom he or she has confided it will be bound by the Fidelius Charm and find it impossible to pass the information on.
Only the Secret Keeper is capable of revealing the secret. That implies other people simply can't reveal it.
The article also states clearly that other people who knows the secret because it has been revealed to them can't pass the information on. Meaning, they just can't say it.