My DS 1 has always been such a sensible little boy. Don't get me wrong and I'm not intending to sound smug - he's had his moments - but on the whole he always seemed so much more well grounded and mature than some of his similar aged friends. Since starting school last sept and also since DS2 came along last July he's become a devious and manipulative little so and so !! Everything he does is seemingly designed to gain attention, good or bad .. over the last few weeks he has amongst other things attempted to hoist a little plastic push along with wheels into a tree virtually directly above unsuspecting DS2, tried to wee into a plastic bag in the house, grimaces and pulls faces if I'm telling him why this is unacceptable and has also started making these mock attempts at cying if something doesn't go his way. He's not always like this and thinking about it, it usually kicks off when I'm on my own with the 2 of them. I dread after school until DH comes home. We do try to give him attention, lots of praise etc and we suspect he's probably jealous as DS2 is such a smiley baby but obviously the attention is often not the undivided attention he craves and misses. Does this sibling rivalry ever stop and has anyone else experienced these character changes ?. Any advice ? Thanks Louise.