"Your new girlfriend has a controlling nature. I'd tread cautiously if I were you."

John stared at his flatmate and then shook his head, opting to pour a coffee and get some of it down before finding out what had prompted such a bizarre declaration. Stephanie was a lovely girl, and in his opinion, they'd had a good date. A very good date.

John took his place at the table and sipped at his coffee. He had a bit of a head, and wasn't feeling particularly bright. The pages of Sherlock's newspaper rattled. John scowled at his flatmate, wishing he'd get on with dropping whatever bombshell he'd observed that was meant to send yet another one of his relationships to the scrap heap. Sherlock turned another page. And then another.

His patience gave way. "Oh all right. You only met her for thirty seconds. How can you possibly know that?"

Sherlock didn't even bother to lower his newspaper before he began his analysis. "She came to the flat. You didn't pick her up or meet her at the restaurant. Thus, she was establishing a dominant position from the start. According to her timetable, you were running late, even though your table, which she booked, was for 8:30. She called you 'John Hamish Watson' to chivvy you along." Sherlock lowered his newspaper, folding it neatly instead of dropping the pages to floor and looked up. "That's behaviour generally reserved for parents and child minders. I was given to understand that she was neither."

John did his best not to look annoyed as he replied, "Stephanie is a stockbroker."

Sherlock raised an eyebrow. "I see she's also insecure and jealous."

John had his cup raised half way to his mouth. He set it down on the table, sloshing coffee over the brim. "And you base that on?"

Sherlock pointed at his throat. For several seconds John looked back at him feeling absolutely clueless. He got up, went to the bathroom, and studied his reflection in the mirror. His eyes widened as he noticed the prominent love bites on either side of his neck. When he returned, Sherlock was still waiting, looking even more smug than when John had left him.

"Normally, I'd chalk such bruising up to the over enthusiasm of a careless lover, but those marks are defined and speak of intention. She wants anyone who sees them to know that you are hers.

"My conclusion is that at some point in the evening, possibly as late as the cab ride to her flat –" Sherlock made a moue of discontent. "No, I think earlier, at the restaurant. You said or did something – unintentionally, of course – that provoked her."

John stared. It was like Sherlock had witnessed the entire date and not just the first few minutes. He had smiled at the server, a very pretty young thing, and Stephanie had gone absolutely frosty and then excused herself from the table. When she returned, it was as though the incident had never happened.

Later, when they got back to her flat, she had shoved him down onto the sofa, straddled him, and pounced, kissing him with a wildness that had literally taken his breath way. She'd nipped and sucked her way over his face and throat, and – John's hand went to his neck. She's bitten him hard enough to make him yelp. He'd laughed it off, but she did it again, leaving a twin mark to the first.

The sex that had followed had been great, he'd been totally sated and completely boneless afterwards. But there hadn't been any curious first time explorations. Stephanie had set the pace, instructing him how to touch her and when. Every time John had tried to slow things down she had done something that had put her firmly back in control. At the time, he had found her assertiveness hot. Now, Sherlock's analysis made him examine the encounter in a new light, one that made him feel a bit used.

"Far be it for me to get involved in your love life -" Sherlock poured himself a warm up to his coffee and then picked up the unopened post, sorting the letters into two piles, the larger of which he shoved towards John. "- but it's entirely likely that she'll make a habit of marking you. You may want to invest in more high collared shirts and jumpers. That is, of course, if she doesn't just insist on a tattoo."

"Tattoo," John repeated. He found Sherlock's confidence in the likely progression of events faintly alarming.

"Oh, I'm sure it won't be anything too ostentatious." Sherlock's tone was dismissive. "She seems the sort to want something like a heart and chain. She already has a key on her ankle. Very smart of her. She doesn't have to get re-inked each time she has a new man in her life."

John huffed a frustrated breath. It was almost as if Sherlock were the jealous one. But that, of course, was absurd. "Why? Why, Sherlock, do you do this to me?"

Sherlock looked up from his letter. The paper was heavy and even from the back side, John could see a heavy crest marking the top of the page. "Do what?"

"Pick apart my dates. Yes, the name thing was bad. When she asked me what my second name was, I thought she was just trying to get to know me better, I didn't think she'd actually want to use it. And not like that." He pushed his palm over his face. "God. I felt about six. And I did irritate her in the restaurant. It was totally innocent. All I did was smile at the server after she'd brought me a new fork."

His phone rang.

"If that's her, I'd plead a previous engagement," Sherlock suggested. "She already doesn't like me, so feel free to use me as a scapegoat."

John just shook his head as he pulled his mobile from his dressing gown pocket and glanced at the display. Sherlock was right. It was Stephanie. He was also right about her feelings towards him. She'd hinted broadly about a furnished flat for let in her building. One without peculiar odours or odd décor where John could be quite comfortable on his own, when he wasn't with her, of course.

Sherlock held up the letter. "As it happens, we do have a case. How does a week in Switzerland sound?"

John killed the ringer and let the call go to voice mail. "I'll go pack."