Stuck in middle of Adult DD’s

Is DD2 more emotionally independent or has she just had to be?

She thinks DD1 just needs to accept the consequence of her decision and stop trying to get us to change our minds. DD2 says she will be angry if I disrespect her boundaries

You write as though you and DD2 are a couple jointly parenting DD1.

At what point will B be forgiven and DD1’s choice of boyfriend respected? Once they move in together? When they’re engaged? When they’re married? This is silliness. You should be teaching DD2 that punishments don’t last forever.

I can't believe you've allowed DD2 to dictate all this for a year now. It's just batshit.

Either they're both allowed their boyfriends' over or neither of them are - and that's a decision for you to make. Not your daughter(s).

Jeez stop pandering to them. They're adults but are behaving like spoilt toddlers.
Your house; your rules. Both should be treated equally whoever their boyfriends are. They can always move out if they don't like it.

So yes, you’re compensating DD2 at the expense of your DD1. You’re allowing her to wield power over her sister because, why? You think she’s earned it? It’s her turn? Her sister owes her? Does DD1 deserve punishment for having a relationship with her father when her sister doesn’t? Are you getting your own resentments towards her out by using DD2 as a proxy?

You see her as being to blame for choosing to date this boy and thus exposing the deeper cracks in your family dynamic. You aren’t acknowledging your DD2’s own questionable behavior in this, and as such I doubt you have any intention of tackling it.

Therapy may help.

They both need to move out.

They're stuck in their adolescent relationships and roles and that's unlikely to change until they live separately from you and each other, away from their childhood home. They aren't (and can't really) handling conflict like two adults in a houseshare or adult family members with their own homes because they are still siblings at home with mum. You're trying to be a parent to your children living at home having sibling squabbles but also not treat them like children while not being able to tell them to just leave each other to live their lives... it's all impossible.

There's no guarantee that they'll ever be good friends, but staying in this set up is only going to add to the resentment pile. Give them both a timeframe for them leaving and (if you're able) lay out what financial assistance you can provide for what length of time.

No, they both have two parents. You aren’t required to compensate DD2 to the detriment of her sister because of her choice not to see him. If indeed their father is as bad as you say, DD1 isn’t in a better position by having a relationship with him.

You have a choice as to whether to continue the dynamic. You have a responsibility here too, that can’t be shrugged off with a ‘not my fault’. Similarly, you cannot use your ex’s poor parenting to excuse your own - ‘he’s worse’ does not make your own attitudes and actions good. IMO it’s increasingly apparent that you favor DD2.

I hope both of them can eventually break away from this shitshow of a dynamic.

Are you sure DD2 is more emotionally mature? She doesn't seem to be handling this in a very grown up way.
DD1 having more of a relationship with her dad doesn't mean she only needs half a mum.
All sounds incredibly unhealthy.

This.

DD2 needs to grow up & get over it!

If i was your dd1 i’d move out & leave you both to it as you’ve made it clear you’ll side with your other daughter

I would say ‘no problem, no boys round until they both can come round’

thsts the only way it’s equally respectful

Do you see it as different, or lesser? DD2 is less of an emotional burden on you, and supports your relationship in a way you prefer. Your attitude towards DD2 really does read to me that you consider her to be yours, whereas DD1 is her father’s. You’re not breaking free of a harmful dynamic, but reinforcing it.

Unless what he said was particularly awful, it sounds like a run of the mill teenage squabble. They're adults now and DD2 needs to stop holding it over her sister.
He's obviously not awful or you'd be very concerned for DD1. You need to stop picking sides and let them sort it out amongst themselves.
Your household dynamic doesn't sound very healthy. It's probably best for you all if they both move out - put a stop to the competition and favoritism.

‘her decision…and stop trying to get us to change our minds’

Fucking hell. She sees this as you and her versus her sister. Not only that, but that she has greater authority than you in your own house.

It very much reads to me like you’re stuck in the dynamic of DD1 being on the outside of your family, whereas you and DD2 are close knit. You risk alienating DD1 entirely, and it’s obviously up to you whether that’s something you consider to be an acceptable outcome.

I also suspect that DD2 may be using this as an opportunity to punish DD2 and assert dominance over her, and it’s actually more about that than it is the boyfriend.

I would ban both boyfriends and say you won’t take sides and both are not being fair to you.

They can conduct their relationships outside of your home or move out.

Also dd2 should NOT be made to feel wrong for being upset or angry about the situation. She should not have to let go of any anger towards this man, how she's treated by dd1 and your inability to protect her. Like it or not, try your best or not, victim yourself or not you have failed her.

The more you comment the more I'm confused as to how you don't see DD1 is the problem here?
The historical context is your ex bullied dd2, and dd1 picked up on his attitudes and followed suit until dd2 was able to stand up for herself with (it sounds like) limited support from you.
Now DD2 is trying to stand up for herself by saying someone who has made crude comments about her body shouldn't be allowed into her home, someone who caused her to loose friends and someone you dd1 sided with.

Dd1 is an adult and can date who she wants but she needs to go touch grass if she thinks dd2 should suck it up and you need to have a long think about why you allow dd1 to act this way.

you can see from both girls point of view how they both feel they are in the right.

I think the solution would be one which respects both of their positions, as well as yours as their mother, and in order to find a solution like that you have to believe it’s possible, be willing to think creatively, and then get them on board to do the same.

I can see a situation, for example, where if DD2 really feels heard re her feelings that she might be able to also see her sisters perspective and agree that for now he can come over if it’s prearranged so she doesn’t have to see him (if she’s out or whatever), and that DD1 understands that work needs to be put in in order to get to this.

they both do need to recognise each other’s positions but they will only be able to do this if they also feel heard. One of them will have to make the first move and be the adult.

Otherwise a family therapist might be able to help, it might not be possible for you to mediate this. if I was you, I’d be trying to learn some skills by reading about mediation and family therapy, there’s probably quite a lot of stuff you can do.

So what he said was horrible enough for you to be concerned about DD1 dating him? Hmm. Gut instincts are not often wrong.

I guess it’s down to semantics but leaving a job because I dislike someone isn’t the same as losing a job. You left because you wanted to. DD2 is being a bit disingenuous in framing it as losing a job.

And I say this as someone who’s also looking to change jobs due to disliking a couple people.