John shivered at the words, shivered as they flowed over him. It helped put him in the right mindset. He was here to serve, to obey, to please.

He moved forward just a bit, and began to untie Sherlock's shoes. He was careful as he slid each shoe off and then pulled the socks off. He was pleased to see the man was well manicured.

He leaned in and licked along one toe and up the top of his foot. John then moved his head, licking along the skin. He didn't do anything more. Sir hadn't commanded it. He was to just use his tongue now.