Sam and Dean were both in critical condition and there was no medical way nor Angelic way to save them. So instead you made a deal with a demon to save (Sam/Dean) in return for your soul, while Ana made a deal with Lucifer to save (Sam/Dean) in return for her agreement in returning to hell and ruling the demons. You were both given a year before you would be taken away.

Do you tell them? Or do you keep it a secret for as long as possible?