I’m frustrated with my partner. We have a son together, 3 years. He has a daughter 4.5 years. We have her 2 days 2 nights a week I look after her during the 2 days why he’s at work but when he home he undermines me e.g. I ask his daughter to eat all her tea she whines at him he tells her to put it on the sink. Lots of little things like this. So now she never listens to me and her and our son fight all the time. Only he gets in trouble by my partner. I’ve tried to talk to him and it always ends up in a fight that I’m a bitch to her or I don’t like her etc. Sometimes I tell him to deal with them and he won’t. I’ve been with him since she was a baby and love her very much. I’m just so lost what to do next. Any advice?