Responses

They are 18 but they were still in high school it’s not like other isekai stories where the MC is older and has people they can actually depend on and plus they went through abuse in their new life. Honestly to me it’s mostly the king that I don’t like mostly because he won’t say anything to the twins, but hey people have different views so idk
To anyone complaining about the twins: Are you completely serious right now? Yes, they might be 20 on the inside, but they are physically children. Every other character should treat them as such. It is not up to them to clear an misunderstanding, but it should be up to the adults to communicate with their children.
Even putting all the trauma aside, explaining their closed off behaviour, it's up to the parents to come forward for the children, not the other way around. All of you are so busy blaming the children, while they had been raised to believe all their new life that their whole famile couldn't care less (even if the belief is wrong). It's not something easy to disprove in years, even less so in weeks.
The progress may seem slow, but considering that they have met their father, what, 10 times?, and he's suddenly sending them away to the place where they got hurt and abused for their whole life? Did you ever consider that the reason they didn't say no is not because "they are children and can't say no" but because "they are actually 20 years old and can comprehend that their abuser is no longer there and it might be better to be by themselves rather than being surrounded by fake affection"? If they were actually children, they might have been more receptive towards the small actions of love and be more honest about not wanting to go there.
I'm just ranting because this is actually one of the few stories that have written post-abuse realistically and not have the MC's miraculously heal from all their mental wounds after a new family. No diss towards "Oh, I can actually eat more than this one bread?", but seriously, abuse goes much deeper than that.
Real abuse can not only cause deep self-loathing and depression, but also DISTRUST. If you understand this, you should understand why the twins are acting like this.