When Cardan kisses her, it tastes like salt. He's not supposed to know how that tastes like, but it scalds his tongue - it's the essence of her. He moves from her mouth, kisses Jude's flushed skin, and wonders why he didn't do this before.
Cardan knows that it was shame that coats his previous actions. He had spent too many nights awake, looking at the ceiling and wondering - how does her skin feel like, under my fingers? (soft but supple, warm, salty)
It doesn't matter. He kisses her because he can, now. Being king is useful for that, at least.
