does he do anything around the house to help? or help with baby?
it may just be he is just as tired.
i know jm and i have argueed before because we were both tired her from looking after dd and me because of work and doing housey things and looking after dd 2!
but then we would wake up in the morning and all would be fine.
he could also just have things on his mind.
being a man i no, we dont like talking about our problems it dents our ego, if we cant sort it then no one can.!!1