Low-key headcanon for this is they're both lying about having partners and are just too dumb to admit they love one another without trying to goad the other on.
... shit, now I actually really want to see that. Like do a Handsome Girl and Sheltered Girl thing, where the prince is trying to disguise that she’s a woman because she doesn’t want to lose the villainess, but then she finds out the villainess is gay because she’s in love with the heroine so she reveals herself and they poly it up. Shit, maybe I’ll write something like that...
This would be genuinely brilliant. And the endgame plot twist would be that men died out 500 years ago, leaving the kingdom inhabited solely by lesbians trying to disguise their genders to blend in with the guys without realizing that the 'guys' were also all just confused gay girls. The truth is revealed when everyone gets drunk and spills the beans at a court orgy, and the next morning, they declare a public holiday to commemorate 500 years of uselessness while energetically making up for lost time. And that, kids, is how World Lesbian Day was created.
I feared bugs too, Nikaidou!
But my fear became hate after living in countryside.
Kill 'em all! (And wash your hands or take a shower, cuz they are dirtyyy)