DP’s son moving in

I wouldn’t go ahead with the purchase without a firm agreement on roles and finances. And even if you are happy about the outcome of that, still think long and hard about whether he has form for making unilateral decisions about things that impact you, even if minor.

It's the lack of a discussion that would make me hit pause. I think it's reasonable for it to be an option that his and your DCs live with you at 19. But I think whose DC would be living where needed to be discussed when you considered moving in together, not when you're about to move in together.

Do both DC know that the other one might also be living in the house? How do they feel about it?

It sounds like there's a real lack of communication in this relationship.

You've both got children that could realistically be living at home with parents. It's hard to believe that the subject of either of them living with you full time should their circumstances change has never come up at any point during the buying process.

Perhaps he is a shit partner but I can also see, from the perspective of being a parent to young adults, that he has no choice but to be gung ho about it unless he wants to fracture his relationship with his child. A discussion means that they are discussing whether to say yes or no to him moving in, but for the partner no is not an option so I can see why he is thinking a discussion isn't needed. I can also see that he isn't looking at this from OPs perspective and I don't think he has approched this brilliantly, but I suspect in his eyes this is a no-bainer. As I said, a heads-up would have been great but he didn't get one himself.

My adult children have both boomeranged for a couple of years now, and my door is always open to them and if I lived with someone, I would expect them to be fine with it too.

YANBU at all. You have lived alone after your kids have started to get their lives together and met someone new who you have decided to get a house with and now have had it sprung on you that there will be another adult living there.
This is not on at all. How long have you b3en together? I would have to pull out. Just explain that you wanted a home together with a guest room, how it was before.

That would be perfect, when the 3 of you are there.
See your future.
Do they have a calm discussion with you, or gang up on you?

What has this to do with anything? No-one is saying discussions shouldn’t be had and options considered but her DP has informed her this is happening IN HER NEW HOME. I doubt very much that she is going to tell her DP her daughter is moving in without any prior discussion because that is what you do when you live with other people, whether they are your children, teenagers, adults, flat mates, lodgers, even pets get discussed before they are bought into a home.

Your feelings matter here op.

I would feel as if mine didn't if a partner suddenly announced their ds was moving in.

It doesn't bode well for your relationship.

If his Mum moans at him a lot, what's to stop the same annoying behaviours at yours?

Why do I suspect that this "moaning" actually means "mum asked me to contribute to the household and tidy up after myself and I don't wanna"

Why wouldn't he have moved in with his dad when it was just his dad though?

But you aren’t objecting to his son (I don’t think!) you’re objecting to your DP making a huge decision that affects the living arrangements for everyone who lives in a house that isn’t wholly his, with no apparent thought of discussing it with you first.

I think that’s how to frame it when you raise the issue with your DP - which you absolutely should - before everything is tied up. His reaction to that will be very telling, and inform where you go next

Yes odd that eh?

OP you'd be mad to buy a house with him. You'll end up running around after two men who give your feelings no consideration whatsoever

His Mum - his actual Mum who would naturally be more forgiving - probably 'moans' because he takes the piss...

The fact your DP has sprung it on you so late shows that it's dodgy and he knows it's dodgy... Yes, 'it's his child', but you can want to live with a partner without wanting to live with their child. Perfectly valid.

Stop now before you're taken any further for a ride. If you're still strong together in a few years time, when (if) DC is living independently, you can still do it. Don't fall for the 'sunk costs fallacy', it is worth writing off the solicitors' and EA's fees - you'd only end up with DP and his DC combined against you, both seeing you as the problem for 'moaning' when you're trying to resist being their house elf...

The question is, does it bother you enough to want to pull out of the purchase?

If no, you just need to have a stern chat with DP about him making assumptions you'd be okay about it and putting down firm boundaries for his son living with you.

If yes, then you need to do it today for the sake of the seller and your individual buyers. But be prepared that it may well end your relationship, because it's a bit of a double standard if your uni son has an allocated room to stay in whenever he wants but your DP's son isn't allowed to stay long-term.

Time to stop and both have a good discussion about this in relation to all your children. Make sure you are on the same page, or keep things as they are now.

Pull out. Pull out today. He has no respect for you, and doesnt view you as important enough to divulge critical information.

"having digested what you have said the other day about your son living in the house full time, and the very notion you hadn't mentioned this to me, just dropping it in conversation rather than consulting with me as a partner and an equal, I'm not going to proceed with the house move, I wish you every happiness but im going to stay put"

Dont go ahead.

You think he would be fine? You should feel awful, you're setting double standards.

Yes, in an ideal world this would have been discussed prior to finding a house to buy etc. but the son only just told OPs partner that he wants to live with his dad full-time. He'd be a pretty rubbish dad if he refused.

I wouldn't be surprised if it was the partner's and son's plan all along.

Whether or not you would have said no is beside the point! The point is that your DP agreed to something that will have such a huge impact on your life without even feeling the need to discuss it with you. You are being ridiculously over-accommodating to think that might be OK.

Sorry but I would be reconsidering the whole relationship.

I can’t believe you have 2 19yos and this hasn’t come up at all during the viewings or any discussion that you’ve had. 6-18 months ago they were schoolkids you had the potential to have 24/7 but now you haven’t even said anything about them having a bedroom in the new house or keeping their stuff there either in the sense of “I really want them to feel at home in the new house and decorate their rooms how they want them” or “We’ll keep the second bedroom as a gym and the third bedroom as an office and we’ll swap the sofa bed for a pair of armchairs in case anyone gets the idea they can stay over”.
I wouldn’t by a house that didn’t have the potential to semi-permanently house one of my adults, whether that’s home after uni, home after relationship breakdown, home while saving to move out etc. But not would I particularly want to live with someone else’s child so I don’t think I would have started down this path with a couple of teenagers on the scene and expected it to go differently. Ultimately he thinks he’s buying a new house and you are moving in and that’s your big problem.

So what did you say when he announced this? Have you discussed since and how do you feel about it?

It’s hard to get a sense of the above from your replies.

That would grate on me too.

I just couldn't quite understand whether you were miffed about him assuming something when you were also making that assumption.

How did it not come up as a possibility for his DC to move in when talking about yours?