Last week when he was bang on 3 weeks old, he does it for me all the time now, never stops smiling for mummy.
He hasn't smiled at OH yet.... BUT when my dad talks to him in baby voice he grins away at grandad.
It made me cry to see him smiling, i thought it was wind at first, but now i know it wasn't all i have to do is say hello to him and the big grin appears.....sooooo cute.