After watching the episode today, Jack was talking to Billy and telling him he needs to claim the baby as his own.

Do you think he will tell???

I can't see Lily keeping it from Cane though because this is the same situation she was in.....she thought Neil was her biological father but found out when she was older that Malcolm was her real dad. She was really hurt, so I can't see her letting that little baby growing up thinking Cane is her dad and finding out later he's not.