To tell her who stole it

You're also calling him shitty for wanting to put his own DD first, so...no.

Could you go over with your dh and having prearranged with her mum, for the mum to bring the item out and ask her daughter to explain herself? Then she can apologise to your dd. She did it, she needs to own it so she won't do it again.
With both of parents willing to cover it up, how does a child learn consequences for their actions, and to be trustworthy?

i am talking to the op whose daughter comes first for her. Answer would be different if the father had written the post.

OP s DD comes first for HER. You're forgetting the other DD should come first to her dad.

Him putting her DD first won't help anything.

This is a very valid point and in the discussion with DD about her stuff being stolen perhaps jealousy can be mentioned. DD presumably will also understand the sadness of not living with her own father any more.
No more lying from anyone though

Your daughter comes first. Do not lie to her.
Your daughter needs to trust you and know you have her back over some partner.

Your partner doesn’t sound good to be honest, he is allowing his daughter to get away with this behaviour with no consequences. She will do it again. Also trying to play it that it will ruin the girls already fragile relationship is bullshit he just don’t want to step up and father his child on her behaviour. Very manipulative.

Time to rethink your relationship with him.

Deliberately stolen then.

So first dad gets them back or replaces them within a short time scale and then you will think about how you will explain it.

However, unless your dd is very naïve or you have had hundreds of unknown people through your home she will “know” who has taken her things and you now have the proof.
Covering it up to avoid your dh dealing with the truth isnt going to help in the long term and lying to your daughter isnt a viable option either - think about it. What if she asks who took them, where did you find them etc etc .

Just because two adults are in a loving relationship you cannot force their children into one. Hell, they might not even like each other and throw in family dynamics and jealousy you have a recipe for disaster.

Your Oh doesn’t want to address the issue of his Dd stealing and wants you to be complicit in keeping it quiet because he doesn’t want her to feel any shame incase she refuses to not come to yours to punish him. He doesn’t care about how your Dd feels because his parenting is coming from a place of fear and his ex isn’t interested enough in her daughter learning her behaviour has consequences neither and doesn’t want to get involved. You know it’s wrong but your up against two passive parents not wanting to rock the boat and your own daughter having to pay the price and feel her belongings aren’t safe in her home and two tier parenting. Your’s and your Oh’s parenting don’t align, your Sd needs her stealing nipped in the bud and for her dad to tell her it’s unexceptionable, she has to return items and apologise to your Dd and if it happens again then there will be consequences. If he doesn’t want to do that then you need to provide a home for your Dd so her belongings are safe as a lock on her bedroom door isn’t addressing the real issue of not putting boundaries down. If it was the other way round your Oh would expect your Dd to face consequences as he would fear his Dd would refuse to come over, his parenting is fear based so he would rather close his eyes to her behaviour l.

I think they also often steal because they want the items they're taking. It may also be in part to an emotional need or desire that cannot be met but that doesn't excuse theft.

I'm concerned about your partners attitude to this

It DOES matter because the girls didn't particularly 'gel'. ie didn't like each other

Why do their needs not count? Why do their feelings come behind those of their parents?

And look at the result...

So, no not ridiculous at all

I'd tell my partner (who claims to be dealing with it) that if the matter isn't resolved by 8pm tonight, then I would be taking the necessary steps to shine a light on the pilfering hands of his daughter and I'd be telling my daughter who stole her belongings.
He has until 8pm tonight to deal with it or all hell will probably break loose.

He doesn't put you or your daughter high up on the pecking order now does he? Please say that you have all your ducks in a row should the need arise for you to separate from him?

Who said it was?

Remember, the stepdaughter will make excuses for her behaviour and may just lie about why she did it.

Anyway, regardless of her reasons, once she has been made to return what she stole and made to understand she will never get away with being a thief without consequences, and your daughter has a lock on her door to protect her from further thieving then you can worry about why.

First things first.

He should be concerned on where their relationship will go from here, but that is entirely his daughter’s fault and she shouldn’t have him covering up her wrong doings to avoid consequences. What is that going to teach her? She can steal from her DSS and daddy won’t make her apologise? Nah. She should absolutely be made to return the items and apologise properly, face to face.

It is then his DD’s responsibility to mend this relationship as she is the one damaging it.

Lifted as in stolen.

If she thinks she has got away with it this time it, it will just happen every time she comes to your house.

I had this with my SD, started small things, i called her out on it and asked why she took it and DP said it shouldn't matter it was just tat we didn't use & phone chargers (he feels guilty he left her with her mother and she can do no wrong). It got prolifically worse after that. DS computer games, but I couldn't prove it. Costume Jewellery, clothes, shoes, money, underwear ffs, she used to go through everyone of my drawers, you know when you can tell someone has had a rummage, she used to go through stuff I tried to stash under the bed. She always denied it and i could never find any proof, and if I did she would find an excuse, or it wasn't big enough to warrant her a telling off from daddy - I did very nearly leave him. Worst part was when I started having to take my handbag to bed with me. If I left my purse out and she called round unexpectedly she would help herself to a few quid. I had a money jar hidden in the corner of our room behind some drawers and curtains, I don't know how she managed to find it but she did, I went to put something in it and it only had small change left in it instead of £1 and 50p, I could prove she did that though as there was a ring in it and i found it in her things. I got lockable make up cases and vanity cases for all my stuff.

She is a lot older now and has matured, early 20s, I don't think she would take stuff now but I am a bit on edge if she ever comes around and goes upstairs to us the loo. But to be honest now she is older I wouldn't pussy foot around her to keep the peace, she would be told outright.

Nip it in the bud, my SD made my life hell for a good 8 years, but she had issues at her mums and DP was reluctant to discipline her - he now knows that backfired.

Empathy. For the person who made her a victim? Good grief.

That’s no reason for OP’s dd not to be told the truth.

Of course there are feelings. As far as she's concerned, your dd has stolen her dad. Your dd gets him full time, she lives elsewhere.

Who wouldn't be jealous of that?

Telling your DD is the least of it. The DSD needs to apologise to your DD face to face and her dad needs to ensure appropriate consequences.

I'd accept nothing less - she has stolen and he's trying to cover it up.

And this isn't a 'step' issue. I'd expect any parent to ensure the right response in this situation.

It’s not about throwing someone under a bus, it’s about giving her dd information about her things so the dd can act accordingly.

The dd can elect to put her valuable things away somewhere safe with that information.

OP has every right to reassure her own child that she is being treated fairly.

So are you going to protect your daughter from her stepsister the thief and get her things back?

Or just do what your husband wants because he doesn't care?

What does your partner suggest happens? Does he just want to pretend it hasn’t happened?

My DD is really particular about her things… she’d really struggle with this .

If it was a biological sibling who had taken these items would you be so keen to throw their relationship under the bus?

I ask because my younger daughter went through a phase of pinching (a vernacular word here in South London , which means stealing) her big sisters things and also, on occasion, small sums of money. We handled it very gently because we didn't want to cause a rift between them.

It wasn't stuff she particularly wanted or needed. And it wasn't because they didn't get on - they were and still are very close. I think it was just a cry for attention (her big sisters was very dramatic and often got an unfair share of our attention) mixed with jealousy of the glamour of big sisters being older.

we knew it was her taking it and a quiet word along the lines of "if you've got X's stuff, you need to put it back in her room before bedtime and no more will be said. If it doesn't turn up we will need to think about what to do next'. It always turned up and the embarrassment of being found out meant the phase was short lived.

This absolutely has to come from her dad. You shouldn't get involved.

Siblings have always taken each others stuff. It doesn't mean they will grow up to be master criminals.

He's right, it will cause tension between them. Welcome to the world of raising teenage girls/sisters. The fact that they are step sisters and don't live together all the time is to a degree irrelevant. Me and my half sister were vile to each other during teen years, always stealing each other's clothes and using the last of each other's 'best'... anything. My parents didn't protect one of us to keep the peace.

Your partner is being weird about this. His daughter needs to face the consequences. What is he teaching her, covering up the fact she stole? She needs to say sorry, return or replace the items if she's used them, and deal with any drama from your daughter that arises. That's how she learns not to nick stuff. Yes, you need to be fair to your daughter, but also fair to the step-daughter - which in this case means, kindly but firmly making her own her shit. Your family will never 'blend' if you don't dive in and lead the way, parenting both of them with empathy. The fair, empathetic thing to do is face issues head on, as a family, not hide from them to keep the peace.