They do sound like a pair or little madams, if they were better behaved no doubt you would'nt dislike them as much, the hygiene issue is'nt their fault or the behavior, BM needs to step up, what does your partner do when they are rude? I know its hard, my sd6 is eating her dinner at the moment, I constantly have to remind her to eat with her mouth shut, all I can hear is chomping and slurping "yuck", sometimes she's lovely sometimes she drives me crazy and I want to run away, I think Im the only one who teaches her manners.

You don't have to like your step kids but there is no reason to live this way. See a counselor who within 2 months should have you understanding why you feel this way and have given you a ton of methods to bring yourself around.

Don't expect to make changes in these kids. You have them 2 of 14 days and no one can expect to have any effect on them with that little time to work. Step back and re-evaluate your role in their lives and let Dad do most of the work. You relegate yourself to background duties such as meal preparation. I.e. things that effect the whole family not just them.

Then disconnect - here's what I did.

I wrote this a long time ago and I hope this helps with your problem. It may not reflect your exact situation but you'll get the idea:
The situation with my step-kids finally got to the point where I decided that my efforts to raise them was futile.
First I told my wife in private what I was going to do and why.
Then I stopped investing myself, time and money in their upbringing. I realized that by conscious choice I could cease being responsible for them or their actions. Neither would I take credit for how they turned out, good or bad. I simply stopped interfering in their lives. This is not to say if they would start a fire on the living room floor I would not intervene. But if they did not do the laundry as scheduled I ignored it. Nor did I do any of their chores. If the trash overflowed in the kitchen - well tough. Mom dealt with it when she got home.
You will be absolutely amazed at the look on a kids face when s/he realizes you don't care enough to even tell their bio-parent they did something wrong. And you'll be amazed at their future behavoir and attitude towards you.
I stayed friendly enough and taught one how to drive when she was old enough. But they could no longer blame me for the consequences of misbehaving just because I saw the misbehavoir. I never told. If they were caught in a infraction it was not my fault. They began to realize that they were responsible for their actions because of what they did not because I caught them.
I would talk to my wife in private if I had issues, but once she made the decision I backed her up 100%.
Once the kids realized I was no longer the ogre they thought I was their attitude changed. I was not their friend, but neither was I the enemy. They came to realize that I had not done those things to irritate them. They in fact missed the things that they had come to depend on me doing. Permission to go to the mall when their Mom was not home? "Sorry, can't do that".
Their mother slowly came to realize that I wasn't overreacting to their actions. In fact I wasn't reacting at all. She came to understand that she would have to control the situation and she did.
With that things got much easier around the house.
Billions of kids grew up in the world without help from me and turned out just fine.

Interesting posts and very honest with your feelings about not being able to love your step kids. I just started another thread about "LOVE" under General which I think is the real issue for many troubled souls and families. The first step towards addressing a problem is realizing what it is, and so at least the step mom who started this thread realizes what the problem is, changing her feelings about the kids is the next hard part.

I'd say get them cleaned up as soon as they step into your place as that will make you feel a whole heap better from the start. You can't have lack of hygiene around your baby. I know you would probably be more minded to disengage, and Sparents including me have found this really works. But, seems to me it's possibly in your circumstances a good idea for an adult to stay engaged at this stage enough to clean their hair. They aren't with you much but if their hair is never washed, they really will not know how to do it at this age. It really might pay off to supervise them and show or tell them how to approach it with lashings of shampoo and so forth. Then at least, when that is thoroughly done, first the hair might have a chance of being a bit cleaner the next time you see them plus you set up a routine of its being expected that they do themselves up the minute they step through your door.

Unfortunately, the kids' rotten behavior is because of their parents, including your SO. I understand your anger at the children, but he's the one responsible in the end. If he tolerates that sort of thing, there's no way you putting your foot down will do ANYTHING but establish you as "the enemy" and "the problem." I have no doubts you would feel closer to them if they were more respectful to you. And this is something that can only come from your SO.

It is crap city, but part of the deal of being the SM is that you can't lead the charge on discipline. I mean, you can, but the kids will just think there's something wrong with YOU, while they and their father are just fine. Even if you gave up your entire life to clean up after them and make sure they don't eat nothing but cheese puffs because their dad is always working, they will still grow up, go to therapy and complain about what an evil witch you were (after making your life miserable for a decade or two).

If you're going to be such a primary caregiver, you and your SO have to get on the same page in terms of what acceptable behavior is, what the consequences for inappropriate behavior will be, etc. And ideally, he will be the one who dishes it out, not you. I personally found myself panicked the first time a child development specialist told me this (my SO and I had so many problems with SD, we went to a therapist to try and fix our home--starting with getting an understanding of how kids my SD's age think (she's 9) and how to blend a family more peacefully). But these days I see it as a relief. She makes a huge mess, I leave it for her father to deal with. She gets way out of line, I file it away, tell him when he gets home, and he backs me up. In my case, it's really helping. I am there to assist, but I am not there to raise her: that is her father's job. I used to feel bad about leaving a mess for him to clean up after a long day's work, but now I don't. It's the only thing that makes him deal with it, and that's the only thing she responds to.

I have also drawn the line on how much of a child care solution I'm going to be. I am not the insta-sitter and I don't want to be. ESPECIALLY when she's not behaving well, he does not pressure me to spend tons of time alone with her and care for her. I am very lucky that he doesn't need me to -- I agreed to settle with them in the town where she's lived most of her life, so there is a network of friends and family to lean on. Again, initially I thought living there instead of where I wanted to was some big sacrifice. But when I see the freedom it actually makes possible for me in the end, I'm happy we did it. Of course I help, all the time, and clean up after her plenty, and all of that. But I'm not left on my own to convince her that even though she only met me a few years ago, she should respect me as a second mother (that's just not how it works).

Boundaries are so important. If you get too upset, then yes, you have to disengage. Don't let anyone make you feel like a bad person for it (these asses typically have NO idea what it's like to step-parent: tons of pressure to participate and make sacrifices as if they were your own kids, but actually zero authority in the end about anything because those kids will always come first for your SO) and don't let YOU think of yourself as a bad person. You chose your SO and he chose you for each other, not because you were in love with each other's children. That's fine. Now you have to find a way to be together that doesn't make you resent him. As soon as that starts...it's over. Even if you never go anywhere.

At times I cannot believe how when a father's children come for a weekend visit he can still go off to work and let his SO care for his kids. For awhile I only had eow visits with my boys until I fought and won full custody, and there was never once that I left my boys in my bf's care. I wouldn't have ever expected for him to care for my kids. Now of course there are times when I have to work or go groc shopping or just out for awhile and my kids stay here at home but before I never did that. Now my ss18 has moved back into our home temporarily and when SO goes to work ss18 either goes to a friend's or with his dad to work b/c I will not have him in my home without SO to watch him b/c he is a little liar and thief.

Ok, now with that rant out of the way, why do you think it's your job to care for your DH's brats?? He should bathe them and wash their hair as soon as they walk in, and then cook their meals and so on. If he has to work then you should put your foot down and say if he has to work on their weekend he needs to have them another time or take time off work b/c you are not his brat sitter.

Why do us wives and girlfriends get dumped with our step kids when clearly we don't want to raise them and we most likely don't like or love them? That in itself makes us like them even less; babysitting for free causes lots of resentments.

don't feel bad, i'm grossed out by my stepkid too....his ability for self-care is about that of a 2 yr old, he's almost 9. if i'm drinking water or something out of a water bottle and he asks for some, i give it to him and there is no way in HELL i'm drinking out of it after his mouth has been on it. he can't wipe his ass and all of his underwear that i have to wash are full of shitstains, NASTY. I truly skeeve him, so you are not the only one!!!

These girls are being subjected to chronic neglect by BM. This is a child protection issue. IMO they ought not to live with her for any stretch, period. She needs very serious professional help. You will get nowhere trying to pick up the slack from this -- nor will anyone. Protective services need to be involved. Neglect this serious will undoubtedly include emotional abuse if not worse.
Going back to your household, you MUST NOT pick up the slack because you will be accused of neglect too. DH must sort this out when he gets in and he must sleep in mini-shifts to do so. My DH works nights. I know this problem well. Do not take up the slack because he must get to feel so desperate that he does something to ensure BM gets help or loses care.
Regarding them needing this much help dressing and cleaning, no you are wrong that they can achieve this at this age IMO, I have seen neglected children in my work and they most certainly do not know how to self-care at this age because they have not consistently been shown how to by a primary carer. Accordingly, they will carry on self-neglecting until taken out of BM's care. This situation for them will only get worse. IMHO carers have to regard this as a compassion rather than a disciplinary issue and teach them patiently and consistently without getting angry.
I think this situation is riding for a big fall and you should give DH a wakeup call. This problem is getting bigger than one person or even two caring for the girls, can handle.

I have just read the stuff about boogers and apparently sores on their lips. They are going to give your child infections, your SO really does need to look at whether it is right for them to remain living with BM.