A.W.
Hi there R.,
My son will be 3 in January and we have been going through this phase for a little while now. His sister is 8 months old, I am guessing that her birth had something to do with it as well. Of course I expected jealousy, but he was a great kid, and then turned into the only thing I can call a monster at times. He does "no nos" for spite. He refused for the longest time to go to the potty. He didnt want anything to do with his sister. Tantrums, biting, spiting, etc... I dont mean to scare you. I kept to my discipline: timeouts and taking things away, and denying him play dates, etc... He still pushes my buttons from time to time but he is much better now. He actually plays pretty well with his sister and has become her protector, every time is cries he comes to the rescue with kisses. So cute. It will take some time, I would say 6 months, and things will even out. He will realize you mean business and arent going to take his bad behavior and he'll also realize that his sister isnt going anywhere. I hope I shed some light on the situation and didnt scare you too bad. Good luck and God bless.
A.