To say this idea is stupid and to tell DH I don't want to entertain it?

Surely your sex life also impacted by sharing with a 3 year old. It's just bizarre that he wants that to continue for another 18 months.

I think a 15 year old needs his own space more than a 3 yo

Here it is: https://www.mumsnet.com/talk/am_i_being_unreasonable/5322907-another-bedroom-one-disagree-with-dh-aibu

Of course your DH is right to be mindful of potential resentment or jealousy his older children may feel knowing your DS gets to spend every night with their Dad and they only get 2 nights a week

Sadly, separated families are a fact of life but this doesn’t mean the OP’s son is penalised because his parents are together?

By the time the loft conversion is complete the older stepkids will be 17 and 19, does your husband intend for them all to have their own room into adulthood?

I think you need to make sure he doesn’t get the smaller bedroom either. DSD in the smallest because she’s only there 2 nights a week, DS in second smallest and then DSS in the next room as there is two of them.

Do your stepchildren have their own rooms at their mum's house?

Why do the stepkids need their own rooms if they're only there 2 nights a week? Don't they have their own rooms at their primary home?

Your husband is being selfish, your youngest lives there full time, he deserves his own room not to have to keep sharing while the other rooms stand empty most of the time.

He really is being completely ridiculous! No way would I be paying 50% of a mortgage to share a room with a DC, when there are empty bedrooms 5 nights out of 7.

"And if it's just two nights a week, he presumably has space to revise at his mum's."

Unless there's also a new half-sibling there who has to have their own room.

I think it's important for step children to feel welcome, but I also think it's important for small children to have their own bed to go to if they are still co-sleeping, so they have a choice about it.

Is it possible your DH is just panicking a little? It's a big change and he wants his children to be happy.

You could put DSD in the smallest room, your child in the middle and DSSs in the biggest. However, if DSD moves out you'd then have to either move your DC into the biggest room and DSSs have the smaller ones, or try to work out which DSS gets the tiny room.

Yes, it would be nice for a child doing exams to have their own room, but children have coped with sharing rooms and revising for years. And if it's just two nights a week, he presumably has space to revise at his mum's.

I would imagine that, if the step sons have their own rooms in their mother's house, they are saying things along the lines that they simply don't want to uproot every week and go and spend 2 nights at your place sharing a room but would rather just stay where they are full time. So would I in their position.

At nearly 18 surely your SS is going to be spending more time out with mates and working a student or full time job so won't want to be traipsing from one family home to another in the week?

The step sons should share, they presumably have rooms of their own at mum's.

YANBU at all. Your DS needs his own room. Your DSS can share for 2 nights a week. Also has your DH considered that at 17 DSD could potentially be heading off to uni soon so wouldn't be spending nights there every week

That was a thread a few weeks ago with the exact same dilemma if anyone can find it that will hold your answers. .

Can you partition the larger room so the dss both get their own space but are still technically sharing?

Agree the youngest needs to be out of your room.

It also, probably over dramatically, makes me feel protective of DS. That his own dad seemingly doesn't care about him having space in his only home so long as DSC get what they want. Rightly or wrongly it hurts.

I don't think you're being dramatic at all.

Of course your DH is right to be mindful of potential resentment or jealousy his older children may feel knowing your DS gets to spend every night with their Dad and they only get 2 nights a week. BUT his suggestion is bonkers and suggests he is massively overcompensating. He needs to recognise that his decision making is being driven by guilt, not reason or fairness and it's making him illogical.
If he's not careful, this tendency to overcompensate could tip over into blatantly favouring your DSC and although your DS is oblivious at 3yo, he won't stay oblivious for long.

Normally i'm all for listening, compromising or trying to reach a consensus but I think you just need to put your foot down. You need, and deserve, your own space. Your DS needs to learn to sleep in a room without a parent present and the longer you leave it the harder it will be for him to adjust. Siblings of the same sex sharing a room 2 nights a week is not a hardship.

Do they have their own rooms with their mother ? If not then what's the problem sharing. And if they do then why shouldn't your son have his own room too.? And I wouldn't give him the smallest room as tell everyone he needs to have all the toys from your bedroom there . Make your room an adult only one .

@User982778 he is being unfair, to you and his youngest DC. Seperated Dad guilt seems to be a problem over and over again, can he not see that he's putting his older children in front of his youngest regardless of need? In your place I'd tell him quite frankly that yes, his older DC don't get to live with him every day, but no amount of seperate bedrooms or money compensates for that, will he feel any better if in the future his youngest says he always felt second best and pushed out?

2% of voters have said the OP is being unreasonable, I’d love to hear why?

No, he’s lost the plot. Not only are they not even using the rooms the majority of the time but it’s awful your son doesn’t have his own room at all! That is insanity and he needs his own space as much as you do.

Get the boys who share a room involved in decorating their room - see if you can somehow 'divide' it so they get a little more privacy.
Whilst it's not ideal, it might help them be a bit more on board with sharing.....

Can you afford to spend some money by creating as much privacy as possible in the shared room. Plus consulting them on paint colour choices etc. This sort of built in divider was on a TV makeover show and looked amazing.

Bunk Bed Room Dividers - What are they, Pros/Cons, and DIY

Another option are wall hung Murphy beds that have a desk underneath that just folds flat when the bed is pulled down. Means that homework can be done at a proper desk then bed just comes down when ready.
IKEA Style Murphy Beds | Wilding Wallbeds

But if you can't afford it, standalone room dividers, strategically placed bedroom furniture and ceiling hung curtains can do wonders.

No. Its just crazy to have 3 rooms that are only occupied 2 days a week and the have 3 people crammed in one room. You and DH need your space and a bit of privacy. DS needs his own room. I'd divide DSS room with a kallax to give them a bit if privacy.

https://www.ikea.com/us/en/p/kallax-shelf-unit-white-30275861/

They can have 2 rows each.