My theory is that Shaia made a secret deal with Toneria, in exchange for Toneria letting Hugo and Theo (who is a beta) be together in peace, he would marry the omega Toneria has chosen for him. He plays lovey-dovey to cover up the secret deal. Also, maybe he had feelings for Theo too and that's why he is into playing a lovestruck beast with Beryl.
they haven't gotten their own story yet. but you can see them in https://www.mangago.zone/read-manga/petit_mignon/ (story for the twins; hugo & shaia) hugo, theo, shaia are childhood friends
All good, but I think it doesn't make sense as long as Daato, Juda, Luard and Kai are still alive, because Juda and Daato had their own trouble with Toneria, knowing about Hugo and Theo being together, I can't picture them to be the kind of patents who're like "take care of it yourself kids" especially while they're still in school. Also over the years Luards position as the head of the family should be stronger than Toneria's position by now. So why would Luard and Juda still let Toneria bully the kids?
Toneria is the oldest member of the family so he naturally is seen as the most powerful. If he’s still alive then he’s still very much in control. So it is most likely that he is forcing this arranged marriage on Shaia too. And as for why the parents and uncle won’t say anything, it’s most likely Shaia had asked them not to. He probably wants to do things his own way. Also, he might be acting like a jerk on purpose so that he can chase away the mc. Instead of directly breaking it off, he wants him to do it instead.
Ok, but Shaia knows that the MC can't leave or he'll loose his home, so right now he hurts him on purpose. He even isolated him for half a year, I can't see that neither Daato nor Juda would agree to this, even if Shaia says to stay out of it. I mean Daato knows best what it's like to be in a position of a powerless Omega without any backround, how could he be fine with his son treating the MC like that, saying hurtful things and using his status to presure him? For me the whole story really doesn't make sense as long as Daato and Juda are still there, because in Remnant and Petit it was shown how strong both of them oppose the mistreatment of Omegas and that they made it clear to Hugo and Shaia that they have to treasure their future partners. (turns out only Hugo listened)
Why doing a hiatus when only the season's final is left and there will be a longer break before the new season starts anyway?