DP’s son moving in

I wouldn’t be happy with the lack of discussion but I’d also expect to offer a home to either his DC or my own in DC in your situation.

Just no. I’d pull out of the house purchase AND the relationship. The son is 19. He is old enough to have a place of his own.

Yeah- this does change it a bit because there is a possibility that your DC will also end up living back with you FT after Uni. So hard to say your DP's son cant live with you when he is implicitly agreeing to living with your DC.

The issue for me would be that there has been no discussion about this. I would understand if after discussion you experienced some disappointment that it was not going to be just the two of you most the time. I would have to say something. No doubt you will be made to.look like the baddie

Would you also feel unable to say no to cooking, cleaning etc for his DS?

I wouldn't be happy with this, especially it not having come up before. What is the reason he wants to move out of his current living arrangements? It will completely change the dynamic of the house, so you have every right to feel upset about it. He also has a responsibility towards his son of course, but he can't just announce something that has never been discussed.
You can either try to make it work, agree it for a certain amount of time, or stay living separately and put buying a house together on hold.

When you say ‘we’re’, does this mean you’re purchasing/ paying for, this new home together? Have your solicitors drawn up legal documents for you both?

He doesn't get to announce he's moving in to your home, he has to ASK and then a discussion, a decision & then if it's a yes rules set in place. Like how much board he will pay, do his own washing etc.

Where is this DC to live in holidays/after uni? Has that been discussed?

It’s a no from me. Firstly it’s a discussion not FYI he’s moving in. Secondly why do you have to live with another adult? I would be annoyed about this. How long is it for? How much rent / bills is he paying? Housework / cooking expectations? Can the son then move his girlfriend / boyfriend in further down the line?!

Random side point but when l bought a property then the mortgage company wanted to know which other adults live there. Was the son included on that documentation?

"Hey DP, can we just have a quick chat about xxx moving in, just want to make it clear im really pleased you'll get to spend more time together! Just wanted to point out, do you realise that you haven't actually told me this is happening, im just wondering if you think you mentioned it to me, because just to clarify- you haven't, and I was a bit surprised yesterday to learn he would be living here full time rather than the usual arrangement!"
(Go in with the 'im sure you just made a mistake' approach)

The ONLY APPROPRIATE RESPONSE TO THIS from him is 'bugger, I thought id told you, god thats really not on, is that okay??'

Any
'Well he's my son so of course its okay' defensive stance from him is a red flag. Its not about his son moving in, its about him not talking to you about it and just doing it on the basis you cant say no.

But you also yes need to have a chat about 'what are the plans for rent/washing/fridge space, and whats his plan from now, uni etc?'

He's a pretty rubbish partner for agreeing without discussing it with OP. The son is 19, he doesn't get to just "tell" his parents which of their houses he wants to live it.

There is miles and miles of ground between refusing his son and the way he’s done this. He should have sat down, told the op about it and that he thinks he has to say yes as it’s his son but he is keen to discuss expectations of this boy, what the op feels she would need in her own home, and he knows it’s not what the op was signing up to buy so understands it may not be something she’s willing to buy into.

Oh, this would be a hard no for me. Living with another adult in your home can be complicated. It's even complicated for their parents. Why does he want to move in with his dad all of a sudden? Any problems at his mum's?

I would not go ahead @maximusss . You risk regretting it and your dp is taking the piss not asking you first.

Say no. Your decision needs to be respected.
Stay in your own home. His son can live with him.
Please don’t feel pressured into doing something you’re uncomfortable with.

Dont do it!
my own stay at home teen is a real problem, lazy, argumentative and rude, expects everything for nothing.
I cant wait for the day they leave.

Do you have children OP?

@Snoken noones asking him to refuse. He's a fairly shit partner because he dropped it into dinner conversation last night without asking her if it's what she wanted. He made a decision for her. At this point she can walk away if it's not what she wants. After they've bought the house that will be far more expensive. Literally no one is saying he shouldn't have agreed to live with his son. The issue is he unilaterally made the decision for op.

Don’t exchange on that property. You and your DP hadn’t discussed and have (understandably) different ideas about this and probably other important things, and his actions on this are cause for concern!

It would change my view of him completely and I'd want to pull out of the whole deal. Surely he can see that having his DS there changes the whole prospect? Will DS contribute financially? Will he be sitting with you in the evenings? Sharing meals? Helping with cleaning, gardening, maintenance? Coming in late at night? The fact that your partner just presented it as a fait accompli is a big red flag.

At least your dp didn’t know for weeks! But this is not cool- you should say to him you’re seriously considering pulling out before exchange if he thinks these are just decisions he can make and casually drop on you, where was the sit down and talk it through? This isn’t what you agreed.