Me, i asked. If only because of sheer curiosity.
Also I wish they at least explained what kind of benefits being a slave give you in terms of protection, to at least justify keeping Merry as a slave.
Like...why would you drag attention to the fact she's a slave by making her recognize that...and not have Dion give a single reason to keep her as one? Even in his mind - at least trying to set it up that it is his trauma with the other fuck messing with his ability to trust her, ANYTHING to explain why him in particular would deflect the question by just saying something "don't worry about it kitten"-adjacent and not free her soon.
Like, I don't even get a hint of a dilemma in not freeing her as soon as they can. But it also doesn't feel like ignoring the fucked-up part of all this is something that all of them are doing consciously at this point, SPECIALLY with that scene of him just telling her to forget about being a slave while still legally being one and not elaborating on the "why".
Edit: hell, rereading the previous chapter, the closest explanation I can come up with, after making some assumptions, is that whoever they get to take care of their house that isn't a slave would be treated as a butler/maid immediately and a bunch of obligatory costs they can't pay would pile up immediately...but like, Merry definitely shouldn't count for it, if only because of a lack of the qualifications given about them. And it feels disingenuous to imply there's no other way of establishing a contractual relationship with a caretaker in their country, even if it requires some loopholes for it.