DSis threatening to destroy my family with secret recording what do I do?

Agree with everyone else that you need to take control of the narrative. Tell you husband (because it IS going to come out at some point now, you need to tell him the context first, and tell him about the blackmail). And also go to the police with evidence of the blackmail and see if you can turn the tables on her. I appreciate it must be painful but it's the only way forward (or better said, the less disastrous way forward).

I would just speak to my DH about it.

Cannot say more without context but you have to get ahead of her story.

Definitely tell your DH first.
by you telling him you’ll be able to do some damage limitation.
Your dsis will paint you blacker than black. It’s best to get in first.
I wouldn’t tell her I’d told him either I’d say to her do your worst.
By seemingly calling her bluff she may not tell him but if she does she’s not coming out of this smelling of roses and the family will see her for what she is and will understand when you go nc with her.
what an utter b!+<h she is. I hope you can resolve this OP.

Explain it to our husband - surely he will 100% believe you??

Then tell her to crack on. Give her no air to think it bothers you. She either will do it, or won't, and NOTHING you say will change that.

So keep your dignity and hope your husband is the man you think he is.

I would think she's unlikely to tell him because she's loving having all this power over you, once it's out she's got nothing. Tell him yourself and you totally dismantle her.

I'm not suggesting that option is going to be a walk in the park btw but it's got to be better than having this dangling over you 24/7. The stress will drive you mad and your sister will enjoy watching the show. Don't give it to her.

You’ll never be able to find peace while she is holding this over you. Take control, tell your husband and tell your sister that if she keeps threatening and attempting to blackmail you you’ll be going to the police.

Well, if you tell him and can give the context, he should believe you.

If you let your sister send the recording, he almost certainly won't.

I rather enjoy blowing shit up and I’d be getting in the family group chat and blowing this thing sky high. Get unhinged OP.

I probably should just tell DH first, but I’m absolutely terrified of how he’ll react.

If your are terrified of his reaction, what on earth did you say?

Surely he might be upset/angry at first but then calm down?

I would just tell your DH, he must know what a fraught relationship you have. Put the context around it and tell him what she is trying to do.

Then tell her to get in the sea with her blackmail.

Yeah the fact that she says it would destroy her whole family I’m guessing something along the lines of “I don’t think DH is DCs dad” - but the full context being “because DH is obsessed with football and DC prefers line dancing”

but then why not just tell him

Yeah is an awful situation but telling her your own version might be best. That way you can control the narrative a little bit and take that away from her. Even if she doesnt follow through this now, she could in the next blow up - 5 years, 10 years etc and you have this around your neck for the rest of your life.
I think DH mght be even angrier if it comes from her.

Tell you DH . Don’t give in . If you have a strong marriage you can I’ll be ok and your awful sister will stop having this to hold over your head . Personally I would simply remove her from my life

Maybe say just the general gist of what the recording is, as people are trying to help but don't know if it's along the lines of "I ran over my DH;s dog and then denied it" or "all of my children actually have different fathers" or " I slept with a female prostitute out of curiousity".
I mean just a hint would be helpful.

And what is the threat? What is she asking you to do? You must be able to word that in a non-identifying way.

Otherwise , I don't think you can expect more than the excellent advice you've already had. Tell your DH.
Was she recording you on her mobile phone? Depending on country and juristiction that can be illegal in itself if the other person is not informed they are being recorded. So you might have her right there .

What the absolute hell? There’s bloody laws against black mail for goodness sake!

Would your family be destroyed? Is it actually terrible or have you blown it up in your mind? Hard to really advise when we have no concept of how damaging it actually is. Though on what you have said, I would be seeking to take back control.

I have a random question.
Would the police actually DO anything? There's no money involved, presumably, DSis is trying to get OP to behave in a certain way and the message, if DH takes it badly might mean the end of her marriage, but it's all very 'mental manipulation' rather than actually profiting anyone - so bearing in mind the police won't even come out if you are being burgled - would they actually, in real life, go to DSis and tell her she was committing a crime? Or is all the 'go to the police' designed more to put the wind up DSis?

OP, you have to tell your DH and then never speak to your sister again.

whatever you do, do not put yourself into a position where she can blackmail you. Come clean to DH. It's gonna hang over you. And cut all contact.

blackmailing is also a crime. I would consider reporting her to the police. But I wouldn't put myself into a position where she can use the recording to blackmail any further.

Tbh I'm not sure why something that isn't that bad when taken in context is threatening to destroy your marriage. That's quite some juxtaposition. Either it's bad enough in context to destroy your marriage, or it's not. And if it's not, then just tell your dh. Presumably he knows your sister has form for being a stirring, back stabbing piece of work, so he'll understand. I couldn't live the knowledge that someone had that level of control over me or my marriage. Tell your dh, go NC with your piece of shit sister.

Depending on your safety- do you have a copy of this recording? Do you have copies of the threatening messages sent by your sister based on her releasing the recording to family? If yes to both I’d say to make it public to all family with a summary of the threatening emails as well (not originals in case of legal problems but I’m not sure on this so do check). Explain your context. Once it’s out then the threats will be the focus. Do check on your safety though. If you’d be at risk of violence or anything else nasty don’t take any risks.

To me it sounds as if you have said something so awful that it will break up your family. I fail to see how you can have said something out of context which has the power to destroy your family. That just isn’t plausible. And now that it’s emerged your sister recorded the conversation you’ve suddenly realised that your DH is going to find out something about you which could break your marriage.

If your sister was that bad, then he’d know that and know not to take anything she’d said seriously. But now you’re bricking it because he’s going to find out the truth about what you think/feel/have done.

You need to come clean, and accept the consequences of what you’ve said.

And lesson learned. Never say anything which can’t be used against you.

Talk to your husband, explain the context and cut contact with your toxic DSis. It feels like the only way for you, otherwise it'll be like the Sword of Damocles hanging over you forever.

She's made a secret recording, why? that's crazy, and is blackmailing you, both are against the law. I would tell DH all about it then report it to the police. Whatever happens you can move on with your life. No contact.

All the more reason to tell him first, then you can fill in the context.

A bit concerned that you think your DH is more likely to end your marriage over an out of context, but slightly dodgy comment, than he will support you because your whack job of a sister is trying to blackmail you. Doesn't sound like much of a husband.

Report to the police. She’s blackmailing you plain and simple.