[Sebastian is too busy to glance up at Spike in turn. He's also too busy to concern himself with preventing any accidental new vampires, seeing as he unceremoniously just lets the boy fall once he's all spent.
There's barely-restrained excitement in his smile as he licks his lips clean of blood, eyes shining and a slight quiver in his movements as he lifts a hand to cover his face, likewise letting his features go back to normal. He remains like that, face hidden for a few additional seconds, saying nothing. Just give him a moment - he hates not being completely collected. But what a rush.]