He is the most ill-behaved 6 year old I have ever met. When I met him he was 3 and so so sweet but this summer he came to our house and he has done nothing but lie and whine and be mean to his dad especially. I am a stay at home mom so I have gotten him to listen a little just by sending him to his room and threatening to take away tv time and other things. I do my best to make sure he is happy and educated. We go on trips to the zoo and the library but idk, it is just so hard to love him when I hardly know him (only see him during the summer and winter holidays the last 3 years) and I have to watch him be so mean to his dad and his little sister (my daughter with hia dad). He steps on her/ kicks her and claims its an accident and constantly says he doesn't like her or any of the things she does. She just turned 1 this week. I can not wait til he goes home on Thursday, tbh.... I feel awful saying that but I need to get it off of my chest. I can't vent to anyone else.

Update: I am sorry, I shouldn't have said he was the most ill behaved 6 year old. He can be very sweet still too. I was upset when writing this because he was just telling his dad that "he ruined his birthday". But thank you for the advice, everything you guys wrote was very eye opening. I never thought that maybe he was upset with all of us. Both his dad and I's parents are still together so we never went through what he is going through