Indeed Potemkin doesn't believe his word for a second, but he's comforted just by Ky accepting the glasses. That's all he cared about, Ky not putting himself through discomfort when Potemkin could just pick up what was needed from his desk. Potemkin was already hushed, but he's quiet as an owl when he feels Ky pick out of his hand.

And feeling Ky's fingers provides even more comfort, but Potemkin stays quiet, letting only his closed mouth twitch a little and his heart rise alone in his chest.