I get annoyed by partners children

[Daddioo]

I've been with my partner for 2 years. We don't live together but see each other 2/3 nights a week and alternate weekends.
Everything about her as a person is perfect to me, she has every quality I'd look for and if it was just me and her I'd have no doubt about her being the person to spend the rest of my life with.
BUT I have 2 children and she has 3 children. All 5 are aged between 7 and 11 and get on great. However, we're quite different in our parenting approaches and our children are equally quite differently behaved.
I'm quite strict with my children, they're well mannered, work hard at school and are very clean and tidy around the house and their mum has the same approach with them so it's how they are.
My partners children are all great kids but have less respect for things. They'll jump on furniture, leave half eaten food laying around, leave lights on, not flush toilets, make mess when eating and just ignore it, all fairly minor really but it all adds up to me not wanting to live together. I'll make little comments sometimes but it goes unnoticed, but we have spoken and she knows I struggle with how 1 of her children in particular behaves.
I don't want a relationship where we live in 2 separate households forever but in reality that's how it's going to be for at least 10 years til the children are grown up.
In my head the relationship has no future but my children absolutely adore her and I doubt I'll meet another partner like her but I don't think it's fair to either of us to carry on when I'm not 100% invested due to the children. I know she will struggle if we break-up but it's got to be the right thing to do hasn't it, despite the pain it will cause her and also my children?

Blended families can be complicated. It may be that you'll have to accept some compromise and that may well be living in separate homes. It's not that bad a solution surely

‘I know she will struggle if we break-up but it's got to be the right thing to do hasn't it, despite the pain it will cause her and also my children?’

Nowhere in there do you say that it’ll hurt YOU. So maybe this isn’t the relationship for you?

If you don’t want a relationship where you both live in different households and can’t live together then the best solution does seem to be to end it so you both don’t waste years on each other.

I know some blended families work but that’s usually when adults have similar parenting approaches or have a joint child.

You don’t spend a huge amount of time with your partner by the sounds of it, a couple of nights a week and every other weekend in just two years means you are still getting to know each other, I thought I knew my partner inside out until we moved in together.
If you have doubts about the situation now then it’s unlikely to improve, your partner isn’t going to change how she raises her children and this will likely cause resentment in future. The more time you spend with the children and they mix with your kids the differences will become more apparent.

It sounds like your partner is more relaxed in terms of discipline and housework, there is nothing wrong with that but if you prefer a more organised stricter approach then it would be very hard to live and raise kids together.

I had an ex who I loved deeply, we were together 18 months and happy before we moved in together but split up 3 months afterwards.
I like a calm tidy house and everything to have a place so it’s easier to find. My ex liked clutter and noise, his kids ran round leaving toys everywhere. The tv was always blaring and no matter how many times I set the table for mealtimes and tried to encourage table manners both my ex and his children ate in the living room by the tv dropping food everywhere and leaving plates piled up. I loved him but we just weren’t compatible.

You could try having an open discussion and see if you could both make compromises and see if there are any changes you could both make. Unfortunately neither of you are doing anything wrong it’s just different lifestyles, it’s unfair to expect anyone to change drastically to please someone else.

I think you know this already and have made your mind up, it might cause short term hurt but better to be honest now rather then keeping something going that you know has no future.