Aww I just loved this so much, I don't think I can tell you how much really.
I loved each of them blaming the other about Lily when she did something to them, and I nearly fell of the chair laughing when she flew through Severus' lab window and out the otheride and all Harry was worried about was that she was OK.
Lily hitting Hugo was brilliant, normally its the boy hitting the little girl, but there again she is Severus' daughter.