My 2 1/2 year old boy was always a very quiet, reserved and sensitive little boy at the baby and toddler groups we went to. His baby sister was born 10 weeks ago and he has totally changed. He goes up to other children totally unprovoked and pushes, hits or kicks them. He also gets right up into their faces and makes an aggressive face at them or growls. His speech is advanced for his age so it isn't as though he can't communicate with people. The other children don't do anything to provoke this behaviour. My first instinct was to stop taking him to groups because I'm so embarrassed and having to stick to him like glue to try to intercept him before he hurts someone but I know he'll never learn if he doesn't socialise. He doesn't go to nursery. If I ask him to say sorry he says no I'm not sorry. No amount of sitting down and trying to reason with him works. I'm really worried. I know that having a new baby in the house is a huge thing for him and so we have tried to involve him. He's so loving and caring towards the baby. I'd love any advice anyone could offer please. Thank you!