So we have recently started living together me and my partner I have 2 kids live here 9 and 17 he has a 17 year old as well. His son doesn’t live with us but stays often, the arguments have started since his son has got a girlfriend there’s a lot of bickering she doesn’t like my daughter and thinks my step son likes her so she has to be here every time he stays, his son is disrespectful he doesn’t ask if she can stay she just turns up expecting tea etc and to stay my step son slags me off calls me lazy and I don’t do anything to my daughter I work cook clean the house and don’t stop he likes to slag everyone off his gf his mum her mum everyone when it suits but expects lifts and teas made I’ve spoken to my partner and he says kids are kids and that his gf can stay and I’m trying to cause trouble by saying she can not stay ? I said a odd night is fine not every single night he comes he’s said he’s going to start looking for somewhere else to live as he doesn’t have a day in things as it’s my house; from where I’m standing it’s me that has no say ? They come in when they want make a mess expesxt me to clean it all up and walk out, I wouldn’t have it from my own 17 year old but I feel I can not say anything to them as he’s not my son and looks like I’m been funny or nasty but for some reason his son is always making things arward giving me and my kids dirty looks asking what his dad has paid for ? I pay all the bills in the house gas electric rent council tax food everything his dad may pay for holidays or meals out but he sees his dad buys everything and tbh my partner sees it the same way I pay for nothing but I pay my bills and anything kids need I can’t afford days out meals holidays as well on top it’s hard enough as it is but no one’s offers to pay towards anything I feel my house has become like a stop gap for ppl to eat and sleep and make a mess and go, it’s me that has no say in anything but the step son and my partner are now the ones hard done by he tells his mum and his gf mum all sorts and try’s to cause trouble yet his dad says he’s a only child and he’s always had everything and been on his own he’s 17 he’s not a baby and what he’s doing is causing trouble his gf does not talk and she try’s to be awkward or makes it arkward the other day I was in the shower my daughter was in too the girlfriend juts walked in my house and was laid on the sofa and said she’s waiting for my step son to come home ? I may be old school but do u not knock on the door or ask if u can come around I don’t get it at all