updated 04/22/2011 AT 3:00 PM ET
•originally published 04/22/2011 AT 4:20 PM ET
Elton John and David Furnish surprised the world last Christmas with the birth of their son Zachary via a surrogate.
But there are still more revelations to come.
The couple have thrown open the doors to their home and their lives for a Barbara Walters special airing on ABC’s 20/20 Friday night.