My partner and I have recently moved in together. I have a seven year old son from a previous relationship, and he has a six year old son. We have recently had a new baby. My stepson's mother died when he was a year old and I met them shortly afterwards. I looked after my stepson frequently during this time. He was a very quiet, sweet and well behaved little thing, though sometimes aggressive towards my the two year old. He didn't try to speak at all for the first six months after I met him. I became very fond of him and affectionate with him, though I saw him infrequently for a period of two years, as I was not in a relationship with his father, and they lived abroad. My partner found bad behaviour, particularly defiance, cute when my stepson was little, believing this to be his nature. I have a young son myself and considered my partner to be extremely indulgent, as he laughed at bad behavoiur rather than correcting it. For the last few years my stepson has started to lie and steal frequently. This was certainly happening before I moved in with my partner- he frequently stole toys, and even money. I do know whether the situation has worsened since I moved to the house, as my partner doesn't seem aware of the extent of the problem, my stepson lies constantly and steals almost daily- from people's homes, from school etc. I have no idea how to deal with this as I am not sure whether this is an emotional problem, which we need to deal with gently, or simply due to my partner's over-compensation and over-indulgence. He becomes very angry if I speak firmly to me stepson. If my stepson is told off or doesn't get his own way he screams continuously. My own son is generally well behaved, though he is harshly punished by my partner for small things like not eating his dinner on time. I do not wish to mishandle this situation by being too harsh, but feel that we need to do something now to help my stepson's stealing and lying to stop. So far I have insisted that he tell the truth and return items with an apology, but have not punished him.