I am going through a similar situation right now! I have a 10 yo grl, and a 7 yo boy and he is the same way with both of them. When I confront him he says--fine i just wont say anything at all! Not exactly the mature approach that I was hoping to get from him.
We also have a new baby, and I know this is stressful. I just cannot put up with my kids being punished for the smallest things all the time--it makes me nervous and sad for them and for myself. I do not agree with his idea of disrespect or talking back and I think that it is only natural for a child to test boundaries and ask a question or make some kind of comment when you want them to do something.
I feel that is is healthy for them to try and make decisions for themselves. When he disciplines them, he then gets mad at them and wont hug or kiss them or tell them that he loves them.
This is the final straw, I have allowed him to do this same thing to me when we have arguments in the past, but i cannot allow him to hurt my babies like that. When I was a child, my Dad always took the side of his wife--and I was always a liar!
I just have a hard time believing that as soon as I leave the house my kids turn into mouthy little brats--and i have told him that i dont believe him. My kids receive so many compliments from others, even complete strangers and I am very close to them. I am kind of seeking advice too--please write back, maybe we can keep in contact or something?