To wonder if it's me or him being out of order..

[mamapotatohead]

Partner told me he didn't want us to be tiger we anymore and was looking for flats, then decided he couldn't afford a flat and to keep the mortgage. At this point my youngest was 2 months old and we have a 6 year old too.
I went to stay with my parents with the children.
This was 6 months ago.
He says me and the kids can move back in and he'll sleep on the sofa, but j can't imagine that'll be a nice environment. He refuses to move out for any days during the week so we can give my parents a break. His family are down south and he won't go live with them.

Who owns the house- is it a joint mortgage? What is the long term plan for the house ?

Yes it's a joint mortgage. He either wants to buy me out or sell x

So he is proposing sharing a house as a separated couple - and if he is having to sleep on the sofa, this doesn't sound like a house in which you could easily have your own space.

I agree with pp, you need to look at what the long-term plan is to divide/share this asset, but in the meantime his proposal sounds less than ideal - a recipe for friction and arguments.

He doesn't seem to have anywhere to go and has a right to stay in the house he jointly owns. So do you. You both need to sort the house out, so you can get money owed and go your separate ways into new properties. It has been 6 months so if the split is serious it should be on the market