So why is it that Rowan just calls Dibs on Helayna the twins back off, but don't back off his WIFE.
You'd think those dibs would be implied lol.
I think the difference is whether or not they would tattle to Rowan.
Either Andras or Jezera could easily just take Alexia and break her into being their obedient sex slave within a week at most. But they don't...why? Jezera maybe because she thinks the long game is more fun. But for Andras, this really isn't his style. The answer is they still need Rowan, and Rowan would stop behaving if they did anything like that to his wife.
So instead of forcing her, they seduce her. Make her give into her desires. Now she can't tell Rowan because she is guilty as well. They just asked Alexia if she wanted to have sex and she said yes. How is she going to tell Rowan something like that?
Helayna on the other hand. Well first lets start with why they would just let Rowan have Helayna. First, Helayna leads Rowan to a path of temptation which make him easier to win over/manipulate. And Second, he wanted so desperately to save her that he was willing to put his wife aside to do so, which means that having her in their clutches is at least equally as important as having Alexia.
Of course, due to the horny ring either twin could fuck Helayna far more easily than they could Alexia. But that ring also means Helayna doesn't have to worry about telling Rowan what happen. Rowan is already aware that she is incapable of resisting so he wouldn't blame her for giving in. Therefore Helenya has nothing to lose by telling Rowan if either twin breaks their promise to leave her to Rowan. Which may lead Rowan to stop behaving, after all if they are going to rape people that he cares about when ever they feel like it, why should he keep working for them.
Howeever if you don't claim Helayna, they will fuck her some to put Rowan in his place, because he does care for her somewhat at least. But once again she's already broken so she doesn't have much appeal to them apart from any effects it would have on Rowan.