Nearing breaking point

Me and partner came to deside that his eldest son who 19 should move out of the flat we share. As he wanted me and kids to be happy and comfy and we were sleeping of a mattress on the floor in he living room. He moved in to his friends house with him and all was well for about 2 months. Til he got accused of stealing from his mate and his mates mum. So they kicked him out. A bit of back story when he did live with us he used the place like a hotel. Would never tell us he was here for dinner and would be like where's is my dinner when he did roll in at 9 or 10pm. He never helped around the house and his room was full of rubbish. Any way he was staying a few nights here and few at his mum's but has since been banned from his mum's for stealing from there so he stays here most nights as my partner his dad says he can't see him sleeping ruff. Ok nor do I but I have taken him many times as well as his mum to sign on and to the council to sort out housing ect but he gives up going to sign on as his life is all about his gf and nothing else matters he say he is applying for work when we know he isn't and just sat on fb all day everyday. He comes with me where ever I go as I don't trust him alone in the house.. but it's getting to the point where I'm gunna break. He is constantly winding my 4yr girl up that she is moaning and whining most of the day. He has no respect for our stuff or my kids and tells them what to do ect when he isn't spoke to be here. Every time I go shopping he is spinning the trolley round with my little girl in it or just arguing with my kids over this or that I public it's embrassing me I just give up and go home sorry for the rant but I'm fed up. He isn't helping himself at all and my partner can't see how much it's pising me off. I don't want to tell my partner to chose as it's his son but he needs to do something I can't have him on the sofa when baby's here as I don't want to wake partner up every 2 hours feeding little man as I can't go else where. What do I say or do I'm at a loose end