I have 3 kids DS1 is 18, DS2 13 & DD is 10 my DS2 is constantly on the case of my DD, every time he's near her he pushes her or says something spiteful, they literally cannot be in the same room together.
She is a very happy child whereas he is a little glass half empty and he seems to get joy from making her sad.
She is mostly very sweet with him, she likes to please him but it's most definitely not appreciated or reciprocated and it's really getting her down.
I've sat them both down many times and tried work on their relationship, he gets upset and says that he'll try harder which he does for a day or so but then he soon goes back to "normal"
Does anybody have any help/advice or have kids that have a similar relationship?