Teenage SD19
Help 
DP and I have been together 11 years. He has three children (SS21, SD19, SD15), I have two (DD20,DS16). We moved in together 6 years ago, for the first year his children stayed just at weekends and holidays. Year two, after an altercation between SD, BM and her then BF, DP's three kids moved in with us full time (initially was supposed to be until things cooled down but they never went back, SD15 has a sporadic relationship with BM, SS21 and SS19 don't want to see her anymore).
We have all had our ups and downs but the biggest issue is with SD19. She's been rude, demeaning, demanding and hysterical for years. Bizarrely, the more stable and secure our home life gets, the more she acts out. It's honestly like she's addicted to drama and tantrums. DP and I are at our wits end.
Last year I set some boundaries with her (I think up until then she figured I was weak) and since then she has waged a campaign of hatred against me particularly with DP's mother and two spinster sisters. (The three of them live together and need no encouragement in tearing down others, particularly if they're doing well)
I've pretty much disengaged since last summer after a disastrous foreign holiday where she clung to DP like a leech, walked out of rooms when I walked in, was rude to waiting staff in restaurants and contributed nothing but hostility, condescension and drama for a week. It's like she doesn't like to see anyone enjoy themselves.
DP and I are at the point where more boundaries need to be set with her as she is now using our house as a hotel, again without contributing anything but a bad atmosphere. The whole family tiptoes around her as she's so volatile and hysterical. DP has tried requesting, coaxing, begging for better behaviour and more recently demanding it on the threat of kicking her out.
Strengthening the tone and boundaries have made her up the ante even further where she then went running to DP's mother and sisters' house for a week to basically be pandered to about her wicked witch of a stepmother. She returned home yesterday, thinking that everything would have blown over. DP thinks she is trying her best again (e.g. she "cleaned" the already clean kitchen which is more about power/control of what is ultimately my domain than actually contributing to the household. She was also "nice" to her put upon younger sister who suffers most from her moods/hysterics)
I'm at my wit's end, deep down I know that she needs us in terms of support/guidance etc but I'm not prepared to be this dog that she and her grandmother/aunts can kick anymore. I'm also not prepared for her to continue to destroy the safe home and environment we have worked so hard to create for our family.
Has anyone been in a similar situation or have any advice? How can the cycle be broken on this?
I cant help but think I've a lifetime of this ahead of me and I'm mad as hell at the time it's occupying in my head
She's an adult who isn't
She's an adult who isn't accepting any support and guidance. Set clear boundaries and protect yourselves. If she wants your support it has to be a two-way street.
Either she straightens her
Either she straightens her act up or she goes to live with her mother - take it or leave it.
Welcome to the site!
SD19 is no longer a minor child that her parents have an obligation to house, she has been an adult for a year. As such, her accommodation under your roof should be conditional on her behaving reasonably well at most times and contributing to the household in a positive way. It doesn't sound like she is doing either, and I would be particularly incensed at her walking out of rooms when you walk in, that is unacceptable. If I were in your situation, I would be inclined to tell your partner that unless he insisted on better behaviour, and unless this was forthcoming, she must leave. If he refuses, that would tell me very clearly that he is not the sort of person that I want to live with any longer. I just could not live with this level of emotional abuse from a young woman - for make no mistake, this is what it is.
Thank you
Thank you Kes for this reply and for the welcome
This is first a SO problem
He not parenting his DD. He letting this happen. He must like being in a circus. At 19 what an Adult. She either follows the rules or finds some other place to live. You can not let this to go on. Or 20 years from now you will be in the same spot. She either has to shape up or move out
There are 19 yo who are married and raising a family.
I always wonder when walking
I always wonder when walking on eggshells is mentioned, if there isn't something more serious at play, as in undiagnosed mental issues. At 19 she should be launching, not hanging around making everyone miserable.
Yes, I'm inclined to agree. I
Yes, I'm inclined to agree. I had genuinely thought at this stage she would be making her own way in life! Not necessarily moved out but definitely more mature and independent.
Re-key the locks. Make it
Re-key the locks. Make it clear that she will not have free unfettered access to the family home or resources. Make it clear why.
"You are rude, nasty and mean. Your victimization of this family and anyone else in it has ended. You are 19. We are not legally obligated to support you in any way. If you want to be a part of this family then you will never perpetrate your characterless behaviorally deficient crap towards any member of this home and family again. Your presence and any support you receive is on a moment by moment basis and if you make the mistake of reverting to your usual toxic idiotic behavior ever again you will find yourself completely cut off from the family and the benefits that come with membership in this family. Do not test us. You will lose."
Let her starve and be cold or hot (as the season dictates) for a while when she pulls her abusive shit. When she is wilted, hungry, uncomfortable and approaches with with some humility re-communicate the message and allow her to re-engage with the family in a very limited and fragile manner. If she gets nasty, boot her ass out and cut her off again.
Lather, rinse, repeat until she either gains clarity or stays gone. Either way, she learns that she is not important enough for her crap to be tolerated, and the family wins.
She can know both that she is loved and that her crap will not be tolerated. Love and acceptance of crappy manipulative behavior should not be connected. Crappy behavior should never be tolerated even from people that we love and those that we love should suffer the consequences of their crappy behavioral choices no less than crappy behavior should result in suffering for those we don't care about.
IMHO of course.
Good luck with this toxic failed family breeding experiment. I hope that the family can be protected from her crap regardless of which way she chooses to go.
Wow
This is phenomenal advice. I feel like a tiger mom about the impact being felt by the rest of the family and you've articulated such a strong approach and strategy. (Not sure I fully agree with your remark at the end about it being a toxic failed family breeding experiment but we can agree to disagree there) Thank you.
Having been an active SParent
Having been an active SParent for 26+ years and having read about countless experiences of SParents having to deal with toxic StepSpawn I do tend to tag ill behaved Skids with a variety of labels due to their behavior.
Since the allegedly
Since the allegedly manipulative SK appears to be the hot topic today, I figured I’d just cut and past what I wrote on another forum.
“Why do I feel like I am the one who has to suck it all up?” Because you are. Your DH has set it up that way. He has let his daughter know in so many ways over so many years that she is the alpha female in the house, or you could say that she is the #1 wife in the home.
He supposedly makes rules or sets boundaries, she breaks them, and then she suffers no consequences, or, even worse, he makes excuses for her. He has trained her to just keep doing whatever she wants to do, because why not!? He won’t hold her responsible for anything. And, then to boot, she gets the added benefit of knowing that she has not only controlled dad yet again, but upset her “Evil SM” yet again. Whoo-hoo! Every SK’s dream and daddy laid it all in her lap.
You do not have a SD problem here. You have a DH problem. He has, for years, been treating his daughter more like a wife and you, I'd imagine, more like a child such as by ignoring your concerns. It is the so popular ever-apparent role mess up that happens so often in step-situations. Everyone has been raised to know you treat spouses like spouses and children like children and in-laws like in-laws, etc. You’d think it’d be a no-brainer. But you throw the term SM in there, and these well-honed and well-tried roles all go out the window. Next thing you know, dad is some kind of a$$ for not giving his little baby girl whatever she wants, so dad, rather than being a man and a dad, gives it to her and over and over.
Where does that leave SM? It leaves her at the back of the familial pack. It leaves her being the one who has to suck it all up all the time. This leaves SM looking for and longing for a husband. She married a husband. She didn’t marry, or didn’t think she married, a patsy enabler of a man who pretty much every time wants to take the easy way out FOR HIM. But what about SM. Why can't DH pick himself up by the boots straps and be a real dad and be able to treat his child like a child, and at the same time be able to be a real husband and treat his spouse like a spouse.
Yes, make sure you set those boundaries, strong with that counselor. Set up consequences and get your DH to agree to them in writing. My guess is he’ll wimp out again. However, if he tries to negate what he agreed to, you’ll at least be able to whip it out and show him.
Otherwise, if you want to save your marriage, then you’ll need to completely disengage from SD and focus only on your marriage to your DH. Disengage. You do absolutely nothing for her. She is your DH’s 100% responsibility, including cooking and cleaning and taxing, etc. for her. He now gets to be the one dealing almost solely with the monster he created. That way, in reference to his own daughter, he gets to be the one to have to suck it all up.
Great Summary!
"Set up consequences and get your DH to agree to them in writing. My guess is he’ll wimp out again. However, if he tries to negate what he agreed to, you’ll at least be able to whip it out and show him."
THIS! I did this and having the agreed-upon Launch Plan was critical in mitigating any gaslighting or changing stories about what we'd all agreed to.
Not saying it was a cake-walk, but having the Launch Plan clearly spelled out on paper & posted in a highly-visible location in our home gave me the back-up my DH couldn't gaslight or guilt-trip me into modifying because, as DH put it at the time, SS "just needs a little more tiiiiime." I had to point out they'd both agreed to it, it was simple & reasonable, and if DH needed "more time" living with SS he could go rent a place and do that, because I was DONE.
Thanks for all the comments
Thanks for all the comments and advice. Based on the events of the past few days it's hard not to be pessimistic about how this is all going to play out. Has anyone experienced a situation similar to this where the relationship between the SM and SD came good?
She is 19 years old not 19
She is 19 years old not 19 months old. With that behavior, she is a write off. So write her off.
Keep it simple. Behave and have a place in the family, don't behave, you aren't family. This is the message that this ill behaved failed young adult needs to hear .... constantly.
Lather, rinse, repeat.
IMHO of course.