My 4 year old DS has always generally been a quiet "easy" child, well liked by other children and adults and well behaved at playgroups and nursery. He is still fine when he's with just me or my husband. However, when he is with his 2 1/2 year old brother he becomes a nightmare, shouting, disobedient and constantly winding up, sometimes poking/hitting his brother, both at home and when we're out - though they do actually get on well when they're not fighting! DS2 has very different personality - feisty, loud, a handful but very interactive and loving - he gives as good as he gets with DS1 and isn't imtimidated by him but that escalates things further.
I'm really struggling with DS1's behaviour together with trying to cope with DS2, and now dread going anywhere with the two of them when my husband isn't round. I can't just sit in with them all of the time though as that makes things even worse. I'm hoping that DS1's behaviour improves when he starts school soon but don't know what else to do.