Complicated financial arrangement (house), advice please ... A bit long, sorry

[Rightsaiddeb]

I don't live in the uk so I'm not asking for legal advice (have my own solicitor where i live) more in the line of morally correct behaviour.
Married to dh over 4 years, both second marriage, with dcs each.
I owned my first apartment before dh1 and kept it after divorce (pre-nup and had to pay him a nominal amount to leave and set up home elsewhere).
Met dh2 years later and he persuaded me to set up new home with him in order to accommodate his dc staying overnight. I agreed because his job/ private schools for dc made it sound he could afford to meet me half way (I had inherited a sum of money to pay for half of a very small house). Turns out he only had 1/3 of his "half", I refused to put up my flat as collateral, fortunately my sister loaned us her inheritance to finance the place we found. He is paying her back in small installments, we both invested equal amounts of money for work to house since then.
We don't have a prenup, but wills stating that our dc get what we own, I.e. my dc get my flat, which I'm renting out. His dc will eventually inherit the huge luxury flat he bought with ex and "gave" her after divorce. He complains he was fiddled by her and her family and so had no more money to invest with me. Still wanted the house to accommodate his kids though (my flat was quite big, but in the suburbs and his kids shouldnt have to travel that far...).
After initially signing a 50:50 home ownership, this was quickly changed to my name only as though we're both foreigners here, only I have citizenship and he could not sign the leasehold after all (expensive and we can only afford lease together).
We go halves on utility bills. Dh doesnt disclose his income to me or his savings if any as he says that I am unfair regarding my present will. Should i die my sister becomes "legal guardian" of the leased property until dc reaches maturity as she "owns" house with me until dh repays her in full. My solicitor put in the clause that dh is legally entitled to live in the house and sister can't sell it. Sounds fair to me. Dh wants me to leave him half anyway already, but can't really afford to repay all anytime soon.
My question: should I offer to repay sister and give him back original funding input? He says when he dies my dc should pay his dc half of worth. Sorry, but I feel ever so taken advantage of? Can't really explain it, but I now feel all this is to see his dc " taken care of" yet again. What about taking care of me, at least in spirit? Just odd... Please help me see straight. Thanks!

If he is paying the money towards the house then obviously he should have that proportion otherwise he could be £1 short & dsis & your kids get it all despite him paying towards it. I doi think you need to sit down & work out what is "fair" within the marriage. Also, yes his kids may inherit the house you say he "gave" to his ex but equally she could sell it & squander all the cash or need it for her retirement or die & any new husband could inherit. I think that should be taken out of the equation & just work on what you & dh2 have.

IIWM I would pay DSIS back, and allow him to pay me back, each year I would change my will to give him the percentage of the house he has paid for. So if he pays the money back 10% per year his share of the house would increase by 5% each year.
I change the lease and everything else to my name only.

Honestly, he doesn't sound like he can be trusted with money and I would be very concerned about leaving him in charge of anything in the will, he sounds like his only concern is getting what he can for him and his DCs.

Redhelen, you sound very fairminded, and tbh I've always been overly trusting. Unfortunately both marriages have made me wary. In hindsight. I feel now I should never have entered into this set up and just let dh "visit" me in my flat. Oh well, too late now and i have to make the best of it. Things are a bit rocky already and I've no doubt the courts would come to a suitable arrangement should we divorce. I'm not planning to atm, just want to lift the fog a bit.
Weareeternal, unfortunately you come closest to my actual feelings, I.e. he can't be trusted. I've closed my eyes and ears to so many inconsistencies over the years, but every misunderstanding boils down to his obsession to do right by his kids. I respect a man who looks after his children, and he does pay over and above maintenance etc. I have own income so they are welcome to treats from him etc. But now it seems regarding other small expenses I'm also responsible for their welfare, never mind my own dc. Dh likes to point out what my dc will inherit, forgetting his will come into a veritable fortune from both sets of grandparents. These are not poor people, just greedy I fear.
I disclose all my income, dh has admitted I took a huge gamble on him initially and he was present when wills were set up. I don't want to be unfair, I've never been mean in my life. Dh behaviour is bringing out mistrust and insecurity I never imagined I'd feel. We are in couple counseling, but instead of coming closer I notice I'm digging in my heels too now and not being my usual accommodating self!

Thanks everybody for your advice. Much appreciated!