To say we cant take his child full time?

He is already not picking up the slack

DP just keeps saying it will work out but im the one that ends up sorting everything (good, washing, school stuff etc) so thats why im stressing about it

You are absolutely being unreasonable to say no to your DSS living with his dad full time. Blending families means you need to always expect this to happen. So yes, he should be allowed to move in full time.

Now, you say you don't have room and the house is in your name, so that means his Dad will have to move out and accommodate his son and himself separately. That's also absolutely valid.

What you can't do is refuse the lad living with his dad full time (assuming this is what he and his dad and mum want).

Just read your update. Your kids DO matter more. To you. And his kids do (should) matter more to him. He can't just leverage your parenting by saying his kid is important as yours unless he's already showing your kids are as important by voluntarily taking on your kids' care equally. He's living with you as a partner and that's fine. But he isn't parenting your kids (he may be assisting you in parenting your kids. That is not the same thing). Men pretend there is no difference, here. But the difference is massive. (It's also probably why he's divorced in the first place. Men often pretend they are contributing to parenting equally by refusing to acknowledge the whole).

What he's saying is 'you'll make it work for me and I can just do the fun boy-bits with my nearly-adult son. Then I won't have to pay maintenance, I'll have more fun money off the back of your domestic labour and established home set up, AND look really good being a great dad'. Don't. He needs to commit to being primary parent for his son in a blended family. If that's what he wanted he would have planned accommodation for it, and he didn't. And if that's what he wants now, he still needs to make a plan for that. Either with you, or without. But it's HIS responsibility to make a plan where he can live with his son. Not yours to accommodate his children. And 'make it work'

Ah, I see.

So you do all the food, cooking, cleaning, washing, sorting kids? It's your house. And what exactly does he bring to the table?

Protect your kids first. You say there's bad behaviour and it's already impacting your DC. Yes, he should prioritise his own too. So he should move out and find one for him and his DS.

But oh no - he wants to stay and 'we'll make it work'. ie. YOU make it work. Fuck that.

This. Unless you can apply for a bigger property that will accommodate 6 people, then DP is being unrealistic. He should move out and get a place for his DS.

Obviously if you were joining assets, selling DP’s home and yours, buying together, the scenario would be different and you should accommodate DP, but this feels a bit cocklodgery… it’s your home, your tenancy. And there’s no room at the inn. Are they even allowed to move in under your tenancy agreement?

DP just keeps saying it will work out but im the one that ends up sorting everything (good, washing, school stuff etc) so thats why im stressing about it

Why is he not sorting things out for his own DS? This shows he is a crap father.

Op I would not want to do this either for the reasons you have said

Suggest to your dp that if it’s something he really wants then a house move is required-

lol why is it fraud
it’s her tennancy

she doesn’t have to add anyone to her tennacy and in this case she is wise not to

I think if it’s not going to work for you and your DC, DP should move out and house his DS.

He is his responsibility, not yours.

It’s your house not dps so you absolutely should get final say in who lives there. However your dp also needs to put his son first so really neither of you are wrong.
You need to consider why you don’t want him to stay and are you being reasonable? It is absolutely valid to put yourself and your kids needs first. If you genuinely think it won’t work then your dp needs to think about what he will do. He could move out and live separately with his son until his son is older.

If there isn’t room in your current council house for another child, and your partner agrees his son should move in permanently, he needs to discuss this with the child’s mother and if everyone is in agreement, he needs to move out and rent somewhere just the two of them.

Yanbu to want it to work for everyone and to have a plan in place beforehand but equally this is something that realistically you both should have been preparing for as a real possibility before he moved in with you. I think in your situation your options are either to house swap/ transfer to a bigger property or look at renting. Or he moves out and his son moves in with him and they both nearby.

I think the reason why he wants to move in with his dad are important here op has he given you a reason you're willing to share? I think the urgency of that impacts a lot on the advice you'll get. For example, if mum is trying to hold boundaries in her home and he thinks your dp will be an easy ride by comparison then it needs to be discussed by his Co parents properly. Whereas if there's real issues at his mums and he's not doing well there then i think you need to move him out in some way. Has your dp spoken to mum and what has she said?

She's not married him. Which is important, because it means he has no rights wrt the tenancy.

Why aren’t you saying how many kids you’ve got in the house? I don’t understand 🧐 have you abducted some ?

So your house is crowded already and there is no room for DPs son . Realistically if his son must live with him then DP needs to rent separately. Only alternative I can see is that you and DP take a sofa bed and your room becomes a child’s room . If that’s doesn’t work for you that’s ok - but you have to expect DP to put his son first and leave . If he doesn’t that says a lot

By “taking on” I mean you accept they come first to the parent, that kids can be a pain and stuff comes up at bad times.

Quite frankly you need to make it work and he shares a room. Yeah your child won’t like it but that’s what you get when you are in a relationship with someone who has children

He has a responsibility to his child. HE has to make it work. What if he said that one of your children had to leave because there isn't space? I put he in capitals because this is his problem to solve. What's he's saying now is too vague and is just not good enough.

Sounds like you’re trying to avoid declaring that your partner lives with you if only your name is on the tenancy?
this is fraud.
sort this out first.
then work out how your partner legally houses himself and his child.

It's something to consider when you marry a man with children. This eventuallity could happen one day. Why have you got so many people living with you, besides your own kids? Could you apply for a larger council house?

Is her partner feeding cleaning up after. Taking her kids to school. It's always the woman who has to make it work. Stick to your guns it's your house your children's house and there's no room

So, you're still being quite vague. Your partner's son is 14. How old are your children? What is the split of boys /girls
How many people are living currently in the 3 bedroom house?
As it's your house and I'm assuming that you're not married, if you so wish then your dp can move out and have his ds living with him full time if there really isn't a way to make the space work (age differences etc )
Then, if it's more a case of your children are much younger and you don't want a teen living there, your dp needs to explain how he's expecting it to work , or you're again looking at dp moving out.
Unfortunately you've partnered with a man with a 14 year old so it would always have been a possibility, blending families doesn't magically work the way either part of the partnership wants. Are they actually looking at more a 50/50 arrangement and he'd be going to his mum's at different times anyway.
You won't be able to actually prevent it (unless you decide that neither of them are living in your house) so best to have an open discussion about what this new idea looks like.

Make a list of everything he would need to do and tell him he will be doing it, not you otherwise he’ll just carry on as usual. It is of course normal for his son to want to move in but will this turn into a bouncing back and forth between parents if things don’t go his way at either home.
You need a big conversation about this with both your partner and his son to outline very clean expectations and the responsibilities he will have going forward. Good luck it’s a tricky situation.

Why would you move this man in?!

This sort of thing blows my mind, you didn’t need to move him in! You will be worse off financially and emotionally, as will your kids.

He needs to move out and provide somewhere for his son to live. You need to focus on your own kids well being, they are your priority.