To believe sis(12) over SD(11)?

Have you checked that the number is correct and that no one at school has put your sisters name to another number on your SDs phone?

Also, if its text you can have a look at deleted messages provided they have not deleted their deleted messages.

It sound odd, but they are both very young and by the sounds of it very vulnerable. Could your sis be jealous that your DS stays with you all the time? You need to speak to DP before confronting either of the girls I think.

I don't think you can effectively throw your SD out when her dad is away - whose house is it?

@Bestofgoodluck it seems from whst you have said there are two vulnerable girls who both need a mother figure (your SD doesn’t appear to have a mother in the picture and you don’t make your Mum sound a stable figure) and they both need you.

and neither think this is fair so some difficult decisions need to be made. Whatever happened and whoever sent what it is clear this isn’t working for either of them. The fact that can do horrible stupid things isn’t just their age it is the situation they find themselves in.
and whst this is showing is you cannot have them both with you while your DP is away

hence some difficult and hard choices need to be made. I know you say he is a present father 80% of the time but currently is that enough?
a hard conversation is needed and one I think without too much blame or punishment for two young vulnerable girls

Of course it's not the option she wants. She cooked up this little plan thinking she could get rid of your sister, and it hasn't worked.

The fact she's continuing to try and force the idea that your sister shouldn't stay anymore just screams guilt to me.

I don’t think you are ever getting to the truth of this but the bottom line is you have your own home and in future if your sister wants to stay then that’s where you go and when your partner is away his daughter will have to go to her grandparents just in case your sister decides to stay . There really is no alternative until one of them either admits sending the messages or the SD decides to get over it .

So in those two weeks you are her major caregiver?

the problem is OP this is highlighting the fact it isn’t working - your SD attachment to you has meant she is jealous of your sister.

as you yourself said they are two very vulnerable little girls who need stability and you cannot give that to both of them you can’t.

and if you chose your sister (which you will and should) then your SD gets abandoned.

there is this idea that high schoolers need less parenting than toddlers - I have 2 it isn’t true they need the same but different and a pattern that was fine when she was smaller probably isn’t one that works now. The 80/20 ratio was good but now it isnt

So there were some deleted messages. Why would SD send them and delete them and not show OP those ones if she were trying to get sister into trouble?

I still think that it could still be either of them.

You're in a really tough situation and you've got two young girls who both have their own issues. I think I'd be saying to DP that you go back to yours when he's travelling and you can see your sister then and SD goes to grandparents.

Are you OK?
Because she believes her sister she must secretly be her mother??

She literally said she would take her sister back to her house and stay with her there, how is she putting her sister before everyone and trying to kick the SD out?
As for wondering where her loyalty lies, what a ridiculous position to take in an argument between 12 year olds.
If her partner has an issue with her reasoning then he is more than welcome to look after his daughter himself.

SD is also not OP's daughter. And whether or not DP needs to be hosting DSis is rather irrelevant seeing as he is not actually there parenting, meaning OP is left to look after two girls who aren't hers.

Wow, that is an awful assumption. And even if sd did it, which I doubt, she doesn’t ’need dealing with’. This is her home if ds is causing problems and they don’t get on, it’s her that needs to clear off out of this child’s space. She is not the op’s daughter, as far as we know, and she’s not the dp’s responsibility to have in his home. She has a mother of her own, sd doesn’t and her father works away and obviously thought he could trust op with his daughter. Clearly that’s not the case, she’s brought disruption into his home and is now prioritising ds over sd. Totally out of order. If sd did do this, it’s maybe a cry for help, she probably feels pushed out of her own home.

What, why? OP hasn't pushed SD out. She has offered to look after her SD so she doesn't have to go to GP as she used to when younger. SD has chosen that option. OP also provides regular care to her DSis. She has previously looked after Dsis at her own place while DP was home. As she's staying at DPs with SD then Dsis has come to stay there. As OP is there 90% of the time it's essentially a second home. If she was there 100% presumably DSis would be there a lot.

Since when do 11 year olds dictate family visits anyway? She also hasn't raised any issue with DSis until now.

I think this a no good deeds go unpunished situation OP! Now people are saying you are abandoning your SD and pushing her out because you want to continue to provide the care you've always provided to your sister.

The issue is that DP is the parent and he is not there. None of this would necessarily come up is DP wasn't working away. It's not on OP to stop looking after her own sister because her DP works away! His daughter is his responsibility.

as I understand it, your SD: edited the evidence, asked you not to discuss it with your sister, and said she wants your sister gone. all entirely consistent with her wanting you sister gone and faking the messages to achieve this.
Your sister, rather than rushing to defend herself, appears confused about the messages and unaware of their contents. which is what one would expect if she didn't actually send them. There's also the issue of why she would get up in the middle of the night to leave a written trail of evidence incriminating herself when she could just have said what was on her mind when you weren't in the room. She's either a wonderful actor or she didn't send them.

I think you need to seriously reevaluate your relationship with your partner and his dd. It seems you want to put your ds ahead of everyone else and if I was him I’d be questioning why and where your loyalty lies! It seems you are determined to believe your sister with no proof either way. How old are you? Is your ds really your dd or are you quite young? Your dp is trusting you with his dd in his home and it comes across a bit like you’re abusing that trust, using his home to care for ds and push his dd out!

You still haven’t I don’t think answered how often your DP is away (it seems a lot) and how often your SD is there becuase I think the answer to those is part of the issue

both girls are looking to you as being a stable loving fixture in their lives and neither it seems know how to share.

you know in your heart that you want to prioritise your sister I think probably as you should. Which means a hard conversation with your DP who has frankly passed far too much parenting onto you - him being away and a Dad isn’t possible I don’t think and you facilitating it simply isn’t helping anymore

some hard conversations are needed I think about the future and where loyalties lie and what you are prepared to be responsible for with your DP because these two girls are fighting over your attention

Wow, this is a really tricky situation you're in. My thoughts have been going back and forth throughout the thread.
Ultimately, I think it's impossible to tell who is lying. I wouldn't be 99% sure that your DSis is telling the truth though.

Even implying that either one of them is lying will probably do some damage to the relationship. I think DP needs to step in and speak to DSD alone while you stay at your own place.

I doubt DSD realises that, even if you agreed to not have DSis in her home, that doesn't mean that things will carry on as normal, just without DSis present. It means that you will be spending less time there and more time in your own home with DSis.

I would agree with passwords/codes on phones, and both being confiscated at bedtimes.

DP needs to reevaluate his job and consider finding one which doesn't involve so much travel so he can he home for his daughter, and do some parenting instead of passing it off to you or her grandparents.

I agree with this.

Also with the poster who pointed out that OP needs to prioritise her family and DP needs to prioritise his.

He is asking a lot from OP, asking her to move into his house to provide childcare for his DD when he’s away. I would take a step back from this, and see if he steps up as he should.

OP has her own home and can support her sister from there. No need for these girls to mix.

Have you thought that she has been saying mean things and that this is her way of trying to prove it

you have a real issue as clearly there are two mixed up little girls - is your SD there most of the time and how often is your DP away?

does she see her mum? It sounds as if he is away an awful lot which with a child that age doesn’t sound workable

I think it's worth considering if your Mum expects too much of you too. I appreciate you Mum has issues, but you've been looking after your sister on and off for 12 years now. Is it helping your Mum improve? What effect is it having on your sister? It is likely in this situation that your sister will struggle in the teen years. Clearly having your sister over is causing trouble in your family unit. If it is your sister, would she have the same issue with you having a baby for example if that is what you wanted to do? You may have to sacrifice an awful lot of your own life in order to cover for your Mum.

It sounds like it's your SD who is the culprit. Think about who has to gain here.
If your sister did it then coming over would be difficult for her - why would she?
If your SD did it then it makes it harder for your sister to come over, so she gains.
It's clear to me. The culprit needs to be dealt with once confirmed. Both girls have a troubled relationship with their mothers so don't need to feel more sorry for your SD.

But if she wanted to make your SD seem deranged, insecure and a trouble maker she might send them from DPs house when staying there to frame SD 🤷🏻‍♀️

OP, not saying your sister has done this at all but just trying to highlight you are obviously going to want to believe your sister. You need to stop trying to blame either girl and find a way forward where your SD is happy and safe in her own home and your sister is happy and safe with you.

It's impossible to say which girl is lying. I don't think you can automatically assume your sister is innocent just because she doesn't act guilty but then you shouldn't assume your SD is behind this because she's being hysterical.

Both girls sound damaged and what is clear is that they are not happy sharing the same space anymore. When your DP is back you will need to seriously reassess your relationship going forward as to me it is clear that you are going to have to care for your sister at your property and not keep having her to stay at DPs property where SD is distressed about the situation for whatever reason. Your DP will rightly have to prioritise his DD and you your sister.