How can I control my frustration at the SKids and not take it out on them or their BD?
I am finding it very difficult lately to not get frustrated with my SKIDS. The eldest is 18, he's a good kid but like a lot of boys he is lazy and thinks he knows it all. He does very little to help in the house, is money obssessed but is work shy and thinks he's owed. The middle is a girl, 15, who acts like a princess and is also money obssessed. The youngest is 12, a boy, and is always there. He stays up too late at night, wants to be the centre of attention and all of them I feel use me for my money. The 2 boys live with my partner, they rarely stay with their BM and are demanding as all kids are. The girl lives with her BM. I feel all of them are disrespectful to their BD, my partner, and I find it very hard to keep my mouth shut. Ultimately, I don't like their behaviour or how they have been brought up. I knew my partner had kids, but I didn't know it would be this hard. I do care about them but I go through stages were I don't like them and I find it hard to deal with as I then feel guilty. I have no kids of my own, I always wanted kids, but now, I resent the pressure they put on us. 
What practical things can I do without getting annoyed and trying to make them see they need to do more to help. The problem is, when I start to lose the plot, so does my partner. We are also all going on holiday next week.
Do you live with him?
Do you live with him? Mostly, you need to disengage. They aren't yours, you didn't bring them up, you don't need to be responsible for pandering to their desires or even their needs. They have two parents to do that.
Let dad deal with them. When they come to you, direct them to dad. When they ask you for someone, direct them to dad. When they want money, tell them no. Want you to buy them something, the answer is ask your dad or say no.
Dad needs to be the one correcting and redirecting this behavior. Unfortunately, if he sees no real issue with their actions or their disrespect, he's not going to do anything and the situation will never change.
No, I don't live with him,
No, I don't live with him, but the plan is that I will. The frustration is that their Mom does v little and their Dad does loads, so I'm trying to help him really. I guess I need to try and do as you say and not get drawn in to it. Do you think it is damaging to the SKIDS to disengage? Or is it more damaging to resent them and lose the plot?
I think it's damaging to make
I think it's damaging to make kids think that they can be nasty to people and still expect to be treated just as sweetly as if they were nice kids. I think it's damaging for them to think that because you're involved with their father, you somehow Owe them. They aren't little kids. One is 18, not sure where you live, but in the US at least, that's technically an adult and no longer a kid.
They're not toddlers, they are more than old enough to understand that their actions have consequences. You can't do much about how they treat dad - he needs to address that himself. But if they behave in an entitled, bratty way to you, it would be better to calmly tell them that when they act that way, you're not inclined to do things for them. And since you aren't their parent, you aren't obligated so they should rethink their behavior.
You aren't going to damage them by disengaging. And really, unless you lose it and start screaming, yelling, berating or attacking them - you aren't going to damage them. If nothing else, you absolutely need to take your money out of the equation. You feel used, so stop giving so much. They won't die if they don't get everything they want. The 15 and 18 y/o's are old enough to earn things they want. They can babysit if Nothing else.
I would also tell you to seriously consider/reconsider before moving in with this man. You don't live there and you're feeling resentful. Of the lack of participation of the kids in the household, of the lack of respect. You already feel used. What is dad doing to correct any of this? Does he give consequences and actually stick to them? Or is he being a push over? Does he see the problems you do, or does he think that everything's fine? If he's not seeing it and actively parenting the kids to correct this behavior, you're going to be miserable living with them.
What's the plan for the 18 y/o? Any talk of college or moving out? Cause if not, you're also likely looking at a house where you'll wind up with 20 and 30 something adults mooching off dad - no jobs, no chores, and no plans to leave.
Oh man, you're so right. I
Oh man, you're so right. I live in the UK, and yes, the 18 year old is an adult and needs to start taking responsibility for his actions and earning his own money and their Dad isn't correcting their behaviour and sticking to it. He is a push over in my view and it seems to me that more and more parents do more and more for their kids.
I need to digest and start finding a way to disengage and not take responsibility for them...and take the cash out of the equation.....thank you