DS almost 5.4 has been behaving like big bully with DD (NT, 3). Some of you may remember DS was diagnosed with childhood autism at the age of 2.5. Well, he has improved a lot since the time of diagnosis to the extent that if he did not have his behavioural problems, he would come across as somebody with speech delay. When I say behavioural problems, it does not mean he has severe tantrum or meltdowns, in fact he has not had a tantrum since the age of 2.8. He cries if he does not want to do something, but will follow the instructions. By behavioural problem I mean some of his actions like if he is sitting on a carpet with other kids he thinks kicking the boy sitting in front of him is funny (he does not kick hard), if he is swimming and somebody sitting by the pool, he will take mouthful of water and spit at them. Or he will run away and continuously look back to see if your chasing him in a place where he is not supposed to like on the road. Recently he has also taken to pushing other kids if he does not want to share a toy. We have been doing big consequences with him like if he spits at the swimming pool, we leave immediately, so he does not get to swim (he loves swimming).
We try to take away whatever he is doing at the time to punish him for his behaviour, but his behaviour with DD is getting extreme. For example, he does not want to go to school every morning, but he knows he will have to, so he will say one screaming no and run to DD and start screaming right on her face until she starts crying and then will quite happily walk to the car. I tried putting DD in the car before him but he will do that in the car if he does not get the chance to make her cry in the house. Sometimes he will go and push her or kick her for no reason to see her cry. He will change the DVD DD's watching for no reason just to make her upset. He does love her as well, so if he does not see her for a bit, he will ask to play with her and give her a hug when he sees her. It seems that he is the boss with DD and he wants to make her do everything he wants her to do. Obviously that does not happen, as DD has a mind of her own.
Any suggestions any body about how to deal with this? Thanks in advance.