Harry hung back out of respect. He knew that Hermione was only taking off her dressing gown, but, as every sinew of his body was aching for her, he didn't trust himself to hold in his control at just this mild display of disrobing. His imagination was vivid enough to fill in the blanks his loins throbbed for, and the energies of the palace were treacherous to what should be a secret intent. Everyone from the lowest under-gardener to his Inner Circle would know what was on his mind just then.