I've been with my partner for 6 and half years. He has 2 children (boy age 14 and girl age 11) I have 2 children aged 15 and 11.

he moved into my house about 3 years ago. At that time my partners ex stopped him from having his kids as often as he did and only allowed him sleep overs alternative weekends. I supported him to go to court and an order was granted every Tuesday has the kids, alternative Wednesdays and alternative weekends.  As we was a family and I wanted them to feel welcome I swapped my bedroom to the smallest, as the big bedroom I could split so his oldest and my youngest could share but have their own space. As it's only a 3 bedroom house when his kids come to sleep we sleep downstairs on the sofa bed so his daughter can have a room.

It has been a challenge as I feel the expectations my partner has on my children, he doesn't have for his own. My children have been called spoilt and entitled. That I make them take no responsibility for helping out around the house I.e putting their own clothes away, fetching cups out of their rooms etc. however, when his kids come they leave everything everywhere, dirty clothes on floor, rubbish left in beds etc. 

when the kids are here, their mum rings and texts them. There was an occasion when kids were here and he couldn't find his school tie. Rather than ask us, he rang his mum. The thing is the tie was at his mums, as we had put in his bag when returning to his mums on the Sunday night. My partner was accused of making things difficult and why wasn't he helping the child.

over the years I have been called names from the kids mother, accused of sending them to school in clothes and shoes dirty and with holes in (not true) text messages sent telling me they are her children. I have photos of the clothes they have come here in and sent to school in - too small, holes in, dirty etc.

my partner pays child maintenance to the mum. Once he has paid half of the bills etc in this house, child maintenance, clubs for the children, car to run etc he doesn't have much money left. For this reason and as we are meant to be a family I buy his kids clothes, school uniforms, shoes etc so they have what they need here. When the girl in particular comes in underwear that is 2 sizes too small, I go out and buy new knickers so she always goes home in pants that fit.

the boy at times has temper outbursts usually when asked why he got a negative at school and this year started saying he doesn't want be here, he has phoned his mum and she has collected him. She has told the boy that if he doesn't want to be here through the week he doesn't have to be (there is a court order) partner has tried to talk to her on these occasions he has brought up his behaviour and that's where the outburst comes from, couple of occasions email from teacher can you have a word with x as he's been disruptive in class, x threatened to hit his sister as she wound him up. Partner fetches this behaviour up with x, he starts shouting at us calling us at times stupid, I hate you, will not leave the room to calm down (at times we have locked ourselves out of the house to escape him) luckily these outburts are not as often.

the issue I am really struggling with and has caused arguments over this last year, the kids always go back on a Sunday night, they arrive on Friday from school. They go back in clothes that I often have bought them for them not to be returned. My partner in the past has text to say can I have clothes back and was told 'don't tell me what to do' you are a weirdo and get a life. Kids have gone back in new clothes and when asked for them back - I can't find them, for them to be returned a year later (often then they have grown and no longer fit them)

the boy has football and takes the football boots and kits we bought him for here to his mums and doesn't fetch them back. I maybe wrong in thinking but we provide for when the kids are here and mum should provide for them at hers. 2 PE kits are at their mums that I have bought but yet cannnot be found, so boy going to school without a PE kit.

I have said enough is enough as we cannot keep replacing clothes/shoes/uniforms we have bought them for here. The kids are getting older to take some responsibility of fetching things back (they are very quick to take things back to their mums)  the money I have spent I could spend on my own 2 or put away. My partner has said he will text again for clothes back (hasn't) he will send kids back in school uniform so no clothes back (doesn't happen) he will stop pocket money for them from here so if things don't come back this money can be sued (he hasn't) he is more worried that he will get another shitty text from their mum than deal with the issue. 
 

he doesn't follow up on any consequences for his children if don't put clothes away, leaves a mess etc but called my children spoilt and entitled. I am left doing their washing, drying clothes, feeding them. 
 

alternative Tuesdays his parents come to visit and take his children out for tea, they often come back with new clothes, makeup or clothes. My children see this alternative Tuesdays. As I am helping financially providing his kids clothes or replacing clothes that don't fit or not returned, I don't have the money to take my own kids out for tea. Easter my parents buy all the kids the same Easter eggs, his parents take his 2 kids out and they can chose their own (usually expensive ones) and my 2 get the cheapest. When I said that upset me again we was called spoilt and entitled and his parents were spoiling their grandchildren.

I just feel nothing will change despite all the promises I have had. The final straw that led to this post is that despite 2 PE kits at their mums from our house, he went out to buy another one. His daughters shoes then fell apart and I bought her new ones.

I don't think he will ever stand up to his ex, he is more worried about shitty texts from her than he is about how I am feeling. I have said I have given a lot but feel getting little in return. That I feel am been taken advantage off. He sees the kids go to school with holes in shoes but does not challenge her. He takes the kids to all dentist appointment (this was after I finally flipped, as when I first met him they had never been. He said he had text and got back I'll book them in. I said that is not good enough, she hasn't done it, you have tried for a year, get them registered and get them in, both needed fillings) he takes to eye appointments and paid for the difference in glasses when boy needed them (these are never brought to our house) he never ever challenges his ex over these things as he's scared she will stop him seeing the kids or send the nasty text messages. I can understand his fears of the threats of not seeing his kids, the text messages are not pleasant to deal with but I cannot continue this way feeling all this is his priority and leaves me feeling that I don't matter. 
 

what do I do? Walk away? I do love him and despite the negative post they are lots of positives with my ex but i need to find a way through and think of I am at the point of nothing changes I need to walk away. This has been argument of ours for the last year but nothing has changed. Any words or advice/ suggestions out there?