How on earth, you ask?
Let me tell you.
By countering what is going on. By actively showing his children that he is there for them, that he wants them and that he loves them.
So that would have involved him not moving Bianca into his home upon return from his work trip, but instead living separately, and him going to court for immediate contact (no reason he wouldn’t have been awarded this), therapy for the children and starting to rebuild the relationship from there.
During contact he should have explained to the girls that they don’t have to worry about Bianca, or about meeting her, that he just wanted to focus on them and him. And did exactly that.
He would have asked Bianca to keep a low profile on Social Media and not to mention him at all. This should have been a dealbreaker.
He would have continued to show up consistently for his children, no cancelling contact sessions, showing them that he loves them, not just telling them.
By all accounts, they had a great relationship before, there’s no reason why quick action and understanding and consistency on his part to counter Alice wouldn’t have worked.
But he didn’t do any of this.
He waited almost one year before pursuing contact.
He moved Bianca straight into his home. He arranged pap shoots with Bianca, she posted videos on Instagram of herself filmed in the girl’s bedroom, she posted videos with Ioan speaking in the background/appearing in the background, she posted comments about how happy her and their father were, photos of them on holiday together and then promoted their film just as he told his eldest he had no money to continue paying for her schooling and that she would have to move schools.
He refused his daughter’s suggestion to see him - citing Bianca’s medical issues as the reason. He missed his two first court appointed contact sessions to go to Australia with Bianca.
He didn’t even try to counter Alice at all, in fact, he just fed right into exactly what she was telling the children.
I can’t understand why he made the choices he did.
What a mess of a situation.