Sherlock didn't really answer, he just made an assenting noise and nodded. Being a vampire, he could see quite well in the dark. He had no idea how well John could see. He did see the man smiling.

"You can turn on the light if you like. It doesn't hurt me." He teased softly, a large smile on his face. He could only hope that John heard or saw it.

Sherlock held John's hand, and he put the cup down, so his other hand was free, so he ran it up and down the half demon's bare back.