My step son aged 20 moved in with us in Feb this year. I’d only met him a few times cos though my partner split up with their mother 3 years ago (due to her numerous affairs) their grown up children weren’t told and didn’t actually speak to him for six months. They still believe what she told them that she just didn’t love their dad and wished she’d left him 10 years ago. He won’t tell them any different. Anyhow I gave up my sewing room for him (no problem at all, totally understand) however since he’s been here he’s washed clothes 3 times (when really forced) His room is a shit tip and I mean a shit tip with filthy clothes all over the floor, dirty pots and though he’s been constantly told not to smoke in the house he ignores and smokes in his room which due to space still has some of my furniture in. He has his own loo which is constantly filthy. He has no job and doesn’t sign on. And won’t! He proper pissed me off on Friday by saying no one ever does anything for him and I pointed out he lives here rent free with as much food as he wants, Internet, water, gas, electric. The straw that broke the camels back- his dad asked him to clean his room today 5 times, he tidied but didn’t hoover or clean the bathroom. I’ve bloody had it and told him I’ll get him up at 7 in the morning, switch the Internet off and he will do it. He said you can fuck right off!! His dad knows what I’m going to do and is fine (not sure how fine though as we have argued in the past!) AUBU to carry out what I’ve said I will do? For context my 16 year old lives here and I would never let him behave like this.