You and he see things differently.

Yes, he should coach his kids better, but how tall his kid is not something to pick on a kid for. 

You are at 2 very different stages of life and different roles.  You are on the tale end of mothering.  He is in the middle of parenting and he seems to have previously placed the role of active parent on the wife.  What you are asking him to do is likely something that has never crossed his mind as being his job and, if he starts, he is going to be afraid that the kids will no longer want to come over any more.  And they will definitely rebel against having rules in both houses.  The horror!  Whose fault will that be?  His for not previously being an active parent and only now stepping up?  Nooooooooo.  It will be yours for forcing him to change the status quo.

Your choice is to disengage from the start or back out before you get completely unpacked and date while living separately.  But you are in for a world of hurt and a destroyed relationship if you go down the path you have started on.

Did you see any of this behavior prior to moving in with BF? If you want your situation to improve outside of moving out I would do absolutely nothing for them whether its cooking, laundry, driving, whatever. I'd say hi keep it cordial and plan my own things to do that make me happy and allow your BF to do ALL the parenting. Don't play the mommy role and trust me you'll save yourself a lot of stress.

I think you need to stop being the food police with his kids.  I got in one battle of the wills with my younger SD about food once.. to this day, we still joke about beets. 

Should his young kids have better manners?  Yes.  Do you need to be a smart A about telling her she should use a fork? NOPE.. you don't have to do that.  At that age, I knew how to eat properly.. but I was pretty tactile with my food.. I don't think that's completely abnormal.  Should his kids be better eaters.. eat a more balanced meal?  Sure, but if their father really isn't investing himself in this.. it isn't likely to change and you just come across as mean.

I mean, who cares if the kids like my food?  If they just want a biscuit withjelly?  whatever.. I don't care if they eat a few cookies either.  It just isn't my place or worry to insist they do differently.

If you don't want to cook, don't cook.  but, you can't take it personally when they don't like/eat your food.  Save it for leftovers.. if their dad wants them to eat "better" he will.  You need to keep your opinions on his kid's eating habits to yourself.

If their manners are so bad that they make you ill to eat with them?  institute an adult meal time and a kid meal time.

Don't see this as your problem, and don't try to fix it. 

If the SD starts to eat with her fingers, pick up your plate and go eat in the kitchen/living room/deck whatever.  Let your SO know that if he wants you at the table, he will need to either teach his kid manners, or you two have a separate adult dinner and he can feed them alone.

No longer cook for them, only for yourself, SO and your son. He can make them special meals. 

If he fails to parent them, don't correct them or pick up the slack.  The power struggle over cookies made you look deranged, no wonder she complained to BM that boxes of cookies were being slammed around.   Next time, let DH handle it and vow that it will be the last time you make cookies. 

If you can tolerate his crappy parenting and still want to be with him, more power to you. 

Personally, I would definitely not yet get married, feeling as you do about your fiance's children.  You are around my age (I am 61) and at the grandmother stage of things - you are being forced to deal with a relatively young child constantly, and at our age it's tiring and tedious especially with a poorly behaved child.   If your fiance is going to sulk like a baby for 2 days because you told him some home truths, I would definitely put the wedding on hold.  Who wants to get married to a man who can't parent, or cook?   It will just be a complete pain in the ass for you at the stage of your life when you would expect to start to take it all a bit easier. 

The jelly on the biscuit would bother me. But, the no use of a fork would drive me insane. Dad needs to open his eyes and realize that no one, outside of BM and him, thinks this is acceptable. That would have been my last restaurant meal with them. That would be the last time I made cookies for the house.  

I'd be rethinking the moving in together. If dad didn't have a problem with BM showing up with cookies, it won't be long before she's dropping off meals for them. 

If the problem is just the food/eating, I'd let boyfriend know that until he taught his kids some table manners, I wouldn't be eating at the table with them and I most certainly would not be going out to eat with them.  I wouldn't worry about whether they ate what I cooked or not - not my monkeys.  If there are other issues and you really can't stand being around his kids, there's no reason to make yourself miserable.  Move out. If this guy is that special, date until the kids are out of the house and then move forward with the relationship.  If not, cut your losses.  

First of all, you should not be attempting to discipline these brats or teach them good eating habits or manners. This is not your job, and it is not your role. Your role is to be the best adult friend female in the universe. Happy times only, if it kills you.

Which, from the sound of it, it might. Re-think this relationship. The guy clearly expects you to step into a mothering role, which the children and not incidentally their bio mom will never permit you to do. And in the end guess who's going to be left holding the short end of that stick.

Second, third, fourth the advice to move out and just date this guy until his brats are gone. Meanwhile he can hire a nanny/housekeeper, or find some other sucker to do his work for free.

This is why I never dine with feral pig SD15. 

DH only gets the priviledge of dining with me when the pig is not home.

And his kids is going to work?  I would start think about cutting your loses and move out.  He not parenting his kids.  He does not care to parent his kids,  you want to disengage in a Month.  This is the best time in a relationship m it’s goes down hill from here. 

I can feel my blood pressure rising for you just reading this!! I just turned the "big 5-0" myself, and my SKs thankfully are 23 and 25, my youngest DS is 12 and oldest DS is 18. I cannot imagine having to deal with that at MY stage in life, much less almost a decade from now. I don't mean to be negative, but I can't see this working out in a way that you're happy. Food was the biggest thing we ever had issues about when my SSs were growing up (from being picky eaters to ordering the most expensive thing on the menu and eating a bite or two.) One of the most memorable was when my SSs would insist on pizza on visitation weekends. I had custom chair pads made for round seats for our breakfast table, and my oldest SS (then about age 9-10) would insist on wiping his greasy hands ON MY CHAIR PADS! Sometimes, he'd wipe them on his pants instead, but still! I wanted to stop ordering pizza. Finally, to keep the peace, I just gave in and said to heck with it. I trashed the chair pads eventually and focused on the fact that, one day, my SSs would be grown and visitations would be over. One of the sad things for me is that I was late 20's when I met my DH and now I'm 50. SSs are gone but so is my youth. I can't imagine having to deal with all that BS at this age. I find myself SO MUCH less tolerant the older I get. You deserve peace and happiness at this stage in your life, not stress, hostility and resentment. Honestly, if I were you, I'd move OUT and get some clarity on whether you want to deal with these spoiled, entitled kids in what should be the most carefree days of your life. If you do want to stay with your SO, I'd date him and have my own place where I could go when the SKs came over.

My husband’s daughter (12, almost 13) engages in the same picky eating, picking at her food behavior, too, and it drives me absolutely batty. Sometimes it’s so bad that it’s hard for someone to simply not be bothered by it. So, I feel you.

I resolved to never go out to eat with her again, and I’ve stuck to it. In that area of step life, it has greatly improved - for ME.

If you’re adamant about staying with your partner you’ve got to adopt the whole Not My Circus, Not My Monkeys mantra. 

The way your partner parents is going to be a thorn in your side for years, maybe decades.  Even if you disengage, you will have years of this same crappola in your life.

Ask yourself if after a month living together you are experiencing this, what’s it going to feel like after a year, 5 years?  

Consider moving out, dating, and see what evolves.  Bet you the skids won’t launch at 18 or even at 30 without major parental change.  Are ready to spend the best years ahead on this drama?

you either decide that you will not be present at the zoo during feeding time or you stay in the trenches and fight.  Problem is you are outnumbered and outflanked by guilty Disney Dad.  Either decide "not my circus, not my monkey," I love my SO enough to disengage every other weekend or you leave the situation.  I will avoid eating at a resturant with Skid at all costs since the time he liked the lid of a KFC gravy container in the resturant.

OP just dont. 

I never did and i only said hi and thats it. I get on with stuff round the house and luckily my OH takes the skid out for a bike ride or something to get out the house. I have never bonded nor ever will do and i tell you what. I really dont care about the kid or BM and its brilliant. Im like the other poster i love my SO enough to not let a mistake ruin our lives, she was a one night stand and it wouldnt be fare to judge him for someones devious ideas. My So also knows due to my strong personality that if this kid plays up once he is automatically banned from my house. 

One of the perks for being the breadwinner eh ;) 

He isnt allowed to touch my fridge or cupboards and he asks his dad for a drink never just take. He knows boundaries at my house and no one misses out. Bm and inlaws are not alowed to come round to fuss over the kid in my partners time either. He is a softer man and i am the stronger one. So i kinda help him have a back bone. 

Unfortunately, dad is as much of a problem (if not moreso) than the kids. He clearly isn't running anything, nor do his kids appear to view him as an authority figure. He probably suffers from "divorce guilt" which is a horrible thing for any relationship. If this is the case, he will most likely continue to patronize, cajole and use any other tactic to let the kids know they reign supreme. My fear for you is that the handwriting is clearly on the wall here, but you must remove your rose colored glasses and read it. Very few of these dads change, and SM's almost always are the villain. Offspring rebel in many different ways, through refusing to eat your food, or acknowledge you, never say "thank you", or even consider you "family."

My SD is grown (if only in years, not mentally), but yelled at me in front of her father, "You're not family! You don't belong HERE! How dare you! You're using my father!" Really? For what? No sex-EVER, in all the years we've been together, he can't. To be fair, I knew this upfront, and overlooked it as there is more to a marriage than "that." And, I felt he was an equitable life partner. (That was before he allowed her into our marriage,and let her influence his decisions where I , and my future are concerned, unbeknownst to me for years.) He gave everything away to her and her siblings, (including the home he paid off that we live in), and he has not made provisions for my future financially, so exactly what is it that I am using her father for?? I am clearly here because I love this man like I have never loved another human being in my lifetime.

I really hope you can overcome it, but I am also a realist. The cards just seem very stacked against you at this point. 

Someone mentioned at your age, and at the end of your parenting role, you shouldn't be going through this kind of stress and drama. You raised a good kid, and earned all the jewels in your heavenly crown.

It's easy to say, "I would..." but the fishbowl looks very different from the inside, than it does from the onlooker. There is no easy solution here.

Prayers....

I simply will not take SD15 to any "nice" resaurant or activity.  I then tell SO why and he tells his daughter.  At home I do not cook for SD at all.  I make dinner and do not set her a plate (SD normally won't even bother to show up for dinner).  I do not send any leftover home with SO for SD.  I figure as long as she is treating me like this there is no reason for her to have any benefits of being a part of my life.  SO does his laundry for free at my house.  SD has to use the laundry mat.  ANd this is owrking so far.  SD is getting bitter that we will not do for her and SO explained why.  So now she is the "victim" and we are picking on her.  I let her go tell people what she wants because anyone that knows me knows it's a lie.  I personally don't observe a single person believing what comes out of her mouth because of all her lies and manipulation and SD isn't even good at it.