Who is more in the wrong? DS or DD

Why does it matter? Sounds like tit for tat squabbling which you are making worse by stirring the pot.

Sounds like one or both needs to move out and get some independence. Though I appreciate their finances might not stretch to that.

Would you feel comfortable telling them both to “grow the fuck up”?

I think you need to say to them, "Listen, you two, if you want to stay here you've got to keep things pleasant for everyone. I am not going to live with people shouting and yelling and arguing with each other. I'm just not going to do it and given it's my house, if you do do those things then you will have to move out. At the moment I don't care who moves out, whether it's both of you or one of you or neither of you, but the end result has to be that I live in a peaceful house. Stop acting like children and make a decision whether you want to stay in this house or not."

Why would DD suddenly be rude just because D's was frustrated?

Unless you've missed out a step ie your ds was frustrated and took it out on DD, who reacted because why was he taking it out on her?

I don't see how you can't see this started with your ds. The only way to end this is for each person to take responsibility for their behaviour, and if you and DH are taking sides, it's not going to encourage anyone to actually take responsibility for their part.

So from reading that you have written, your son was upset and frustrated and saw fit to take it out on your daughter. He’s at fault.

Your daughter retaliating is perpetuating the issue however you need to teach your son that it is unacceptable to treat people poorly because they are having a hard time.

Your daughter needs to not wind him up, however she needs back up with him being this way. Your son going on about manners is controlling and wrong frankly, gives me Andrew Tate vibes.

You seemingly not knowing and your write up made me feel that you favour your son over your daughter at least in this situation or at the very least your are dismissive of her point that she doesn’t deserve to receive grief from your son acting out.

You’re either not asking the right questions or you’re being vague on purpose because one (DS?!?) does come off worse than the other.

How did DS’s frustration manifest?
You keep mentioning DD working from home. Did he interfere with that in any way?
How was she rude to him?

Quite 😂

YOU are being unreasonable to give any thought at all as to who was more wrong op, when the only conclusion that can be drawn here is that your son and your daughter were acting like immature, petulant children.
Tbey either grow up and learn to live in peace together or they can move out.

I often say to my kids (now late teens but been a mantra for a while) : I don't care who started it, I care who's going to stop it.

We all have the opportunity to de escalate a disagreement by not engaging, giving space, walking away, saying sorry. Plenty of options. It sounds like both of your kids were in the wrong, doesn't really matter who was MORE in the wrong, that's a really immature way to look at it.

Own your own wrongdoing and apologise for it. If the other person won't apologise, that's their problem, you've done your bit and taken responsibility for the parts which are yours. And no, "I'm sorry for calling you an ugly twat but you did call me a fat bitch..." Just apologise for your hurtful actions. "I'm sorry I carried you an ugly twat. It wasn't respectful and was unkind." End of.

@ML5 if DD is wfh then DS needs to leave her alone and let her work. She needs to leave him alone and get on with it. I wouldn’t take sides to be honest as you weren’t there but stick to the mantra they live and let live or go elsewhere. You are all entitled to a peaceful homelife.

So you don't understand their argument yourself but you are expecting a bunch of internet strangers to be able to decide who is more at fault?

From what I can tell from her posts:
OP’s son has form for tormenting (“winding up”) his sister. She then lashes out in response.
Her son is being a nasty shit to his sister because he’s mad that he had to get rid of his car.
His sister got fed up and called him out on it because she is trying to work and doesn’t need him taking things out on her.
This escalated to them fighting and sending nasty messages to each other.

The reason OP’s posts are so unclear is because she’s trying to minimise her son’s behaviour and blame it on her daughter.

Who cares who started it or who was more in the wrong. It all sounds needlessly dramatic. I’d tell them they need to start acting like adults and treat each other respectfully or move out.

They're adults. Let them be adults and learn how to navigate conflict themselves. I don't think you're doing them any favours getting involved.

Very confused but sounds like they need some space from each other. DS was stressed about car. Stressed out DD who was working. She prob said something nasty and then it escalated. Sounds like small kids! I’d let them stew for a bit and it’ll work it out. Maybe they should just block each other for a bit?

Thry need to grow up, and behave or find somewhere else to live.

No one can say which of your children was in the wrong because no one has a bloody clue what’s happened because your posts are so unclear!!

So basically… your DD is trying to wfh and your DS is at home frustrated and bored. He’s making it difficult for her to work in peace and they’ve argued?! Does he have a job? Can she work in a room where he cannot go in whilst she’s working? Can he car share with you whilst your at work?

In case it helps, I tell my two to ignore the other and walk away if they are winding each other up. Yes, it's not nice that he's being rude to you but it doesn't help to be rude back, so just give him some space.

(I do have a teenager as well, but only one, so he doesn't have anyone to argue with or wind up)

Bit hard to go no contact and block each other if they both live in the same house 🤣

I would just laugh if one of my kids threatened to go no contact with the other, when they live in the same house.

In fact, I do. When my 6yo tells me he will never ever speak to his 4yo brother ever again. (OK, I don't really laugh - but at least it's an age appropriate threat from a 6yo.)

Seriously? How old are you. Why are you picking sides? Let them bicker it out between themselves.