To ban SD from my en suite?!

Oh give over. These aren't her kids. Her own kid wouldn't do this. It's not flattering that her step kids don't respect her or her space or belongings.

I think this thread is weird for the opposite reason. The number of people telling OP she shouldn't care about this is bizarre.

OP this was really out of order and your DH and SCs don't respect you. It's clearly the last straw.

Look, you dont like her and you dont like him - seeing as how its your money in the house, divorce the guy, sell the house, downsize and share custody of the one child you have together - upside of that is no one will ever touch your stuff again, downside is child will only see you 50% of the time.

As much as I know SD is in the wrong, and I would be annoyed too, I have very vivid memories of gleefully swiping my mum’s Pond’s Cold Cream, Oil of Ulay moisturising lotion and squirting myself head to toe in her Anais Anais perfume so… yeah… maybe it’s a good thing that SD feels close enough to you to want to use your stuff?

So there are bigger issues here.

Firstly your SC should not be using your bathroom, should not enter your bedroom and should not use your products, nor should she use your clothing. She should ask and is clearly doing this deliberately to upset you since she has another bathroom, her own products and her own clothes. She has zero respect.

Your husband is not supportive as he has not laid down the law here when you were not there. And clearly he has not had it out with her, which he should as he is her parent.

The bigger issue is that you are working hard, frequently away and your husband, the adult, has no respect for you either as you come home to a dosshouse. I suspect there is a lot more to this than Chanel facial moisturiser.

She was taking the piss using OP’s dressing gown, slippers and toiletries, don’t you agree? In OP’s place I’d really feel she was marking her territory and saying “fuck you” basically.

It's the lack of respect isn't it?

It's a land grab and a power play, pure and simple. Of course she knows what Chanel products cost. Of course she knows the OP's ensuite is private.
Your DH needs to sort her out. Tell him if he can't, you'll be putting a lock on the door and carrying the key on you at all times, and he can deal with any fallout from her.

I completely agree with you OP and I think this is a broader issue of your DPs children understanding the value respecting people’s privacy and value of money.

you work hard to provide for your child plus your partners children. This is about respect and appreciation, not about the cream.

Agreed.

Whatever shades of grey there may or may not be around DSD, none of that applies to DH. This is a grown adult man who has been told how important it is to his spouse to have this one boundary respected. He claims not to have known she was in the ensuite but did know she was in their bedroom, which either means he's lying or he's a complete fucking idiot- what reason would a 17 year old have to be sniffing around in their room?

This. Some ridiculous replies on this thread.

Did you all live together as a trial, before you paid the most of the deposit and bought together? Is the deposit ring fenced if u spilt? I wouldn’t have bothered getting married in your position as the higher earner.

what exactly did u say to SD when you found her in your room? And does DH back you up in these situations?

I don't think you're being unreasonable at all. I'd be livid if my own DD didn't ask to use any expensive products that I have. You put in rules/boundaries, ensured that there are sufficient products/bathrooms for the kids and it sounds like DSD has completely taken the piss and disrespected you.

There is one bathroom in my place, for me, my DS (19) and my DD (12), I wish I had another bathroom!! However, we all ask before using each other's stuff (e.g. if I've forgotten to buy a shower gel/whatever and need to use one of the DC's). My DD won't touch my makeup or my face products. She knows very well the cost of some of them (also how they may not be suitable for her skin type). She won't use my dressing gown (she has her own one) unless hers is in the wash (and again she will ask me first). There's communal stuff and personal stuff, and we don't take the piss.

Our bedrooms are personal space for us all. I go in to the DC rooms to put in laundry, strip/re-do beds or give the place a quick clean (and they do the same for mine), but no dossing in each other's rooms without permission. They also know that I'll go in if I have concerns about anything and need to check rooms (this has never happened). I thought this was all basic manners and respect for each other's things and personal space.

I think the fact that your DH hasn't done anything to stop this speaks volumes.

My (adult) children use my en-suite and if they wanted to use my shower stuff and shampoos I wouldn’t care, why would I it’s a bathroom not a sacred temple and if the want to use a bit of shampoo why on earth would I say no? It’s shampoo not the elixir of life

I think you have your answer. You absolutely shouldn’t tolerate this. Unfortunately it’s going to cost you a fortune to get rid of them, but will be money well spent.

I wouldn’t. She did something she knew was not allowed, treated her SM and her belongings with disrespect and your solution is to reward her. Wouldn’t be mine. Yes, she is a ‘child’ - less than 1 yr from adulthood and more than old enough to know better. This was deliberate with scorn.

I’m sorry but I disagree.

If the OP needs to put a lock in her own home, then the issue is with her DH who doesn’t enforce boundaries when she isn’t there.

The answer isn’t a lock. It’s a review of the marriage and the lack of respect within it.

Sorry but you have a dh issue.
If you want to be angry, be angry at HIM.
lHe knew the bathroom is off limits to ALL the teenagers.
He knew his dd used it when you’re not at home. The bathroom agd all the neatly products. He knew she has done that repeatidly. And he said NOTHING

He is showing he has no respect for you and your things. No respect your what you want.
Believe him.

Completely agree. I would be really cross if someone was using Chanel moisturiser on their legs in a space they weren’t supposed to be in. I do not think it’s worth blowing up the blended family, that seems OTT - but I would be pretty angry.

You shouldn’t have to put a lock, but you should put a lock. As you’re frequently away, it’s the only way to ensure your boundaries are kept.

Fwiw, for me the bathroom wouldn’t be such a big deal, although annoying when there are multiple other options. However, liberally using your expensive creams incorrectly would send me into orbit and I’d be demanding replacement.

Ok I’ve changed my mind having read the OP’s updates.

In this case OP I would put your DD first and get the hell out.

This thread is so depressing and misogynistic.

soooooo many posters really think that as a woman especially a mother ESPECIALLY a stepmother cannot have ANYTHING for themselves. Not even a bottle of nice shampoo. It’s so sad 😢 Just ignore them, OP - YANBU

I don't recall Snow White purloining her stepmother's things.

The use of the bathroom is one thing (I know DC who would do that on occasion) but deliberate use of the costly face cream as moisturiser and your bathrobe does seem a ‘fuck you’

you’ve said you brought more money to the property, earn much more & have to travel frequently for it, have one DC while DH has two, and that he and his DC treat the place like a ‘doss house’.

This set up and use of your resources doesn’t seem to benefit your DC, and you’re pissed off with it, fair enough to consider ending the living arrangements.

I don't understand how pp on this thread don't understand the problem.
Maybe they don't have expensive products (or boundaries) but I completely understand op getting annoyed by this.

Every person in a household is entitled to their privacy and own belongings.