Goodnight shifted, lifted to meet him, and Billy adjusted a little. As with all things, so with this, they fell into each others strides easily. Billy felt impossibly hard behind the protective cotton of his own under garments. His hips shifted against the bed, just a little. Then, he had to lift his hips up off the bed, tuck his knees beneath himself, so that he didn't end up thrusting against the mattress like some overworked teenager.