He's relaxed enough, even though awake-- he's used to being awake before Keith and waiting for him to wake up, after all, not so much lost in his thoughts as focusing on brushing his fingers along his back, listening to the sounds he makes, feeling the way Keith shifts against him.
It's because he's so relaxed, because this feels so familiar, that he just lets out a content hum in response, his words mindless as he answers:] Mmm... Hey, baby.