Lucius had not certainly not expected this sort of response, not from Severus, and it was rather gratifying to know that he had this effect on him, especially when he desired him so badly. So it wasn't one-sided after all, was it? It seemed as though Severus wanted to be touched by him as badly as he wanted to touch Severus.
He reversed their positions, so that now he was atop the younger boy, and his free hand began to snake beneath the other's robes, even as he continued to squeeze his goods.