"Nnnng.." Sherlock rocked back. John was naked, and Sherlock still had his trousers and socks on. He wished that he had taken them off before that, but it was too late for that now, he couldn't wait another moment."

Sherlock rocked down into John's lap. He licked and nibbled at John's neck, tenderizing and wetting the skin. He reared back, his fangs glistening. With a small hiss, he bit down. His fangs easily tore through the skin, into the vessels underneath. His lips suctioned against John's skin, sucking the blood away into his mouth as soon as it pooled at the surface.

He drank eagerly, taking John's essence into himself.