"Look, John, in the interview the security guard, Billingham, said his girlfriend sent him a series of 'erotic texts', at work, which was why he was in the toilets, rather than at his desk, when the thieves disabled the cameras."
"And what was it you wanted me to do again?"
"I don't have any experience of this, it's all so boring and unnecessary, so you need to send me some texts, over the next twenty minutes."
"Keep up, John. I need to know what it's like, what sort of things she might have said, why they had such an effect on him."
"So I'm the girl. Sherlock, where are you..."
"I'll be in my room, twenty minutes, John, a man's alibi depends on it."
The door slams and Sherlock misses the look of pure evil that crosses his flat mate's face.
JOHN: Spread out on your bed, I want to see you touch yourself.
JOHN: Do you take it slow, fingers caressing flesh through fabric, the barest touch. Tease.
JOHN: Or impatient, desperate for skin on skin. Fingers white against flushed red. Hot.
JOHN: Let me see, let me hear your breathing quicken, clothes pushed away just enough. Tangled
JOHN: Slow, to start with, just enough friction, slip, slide of skin, pulse thrumming through
JOHN: Open your eyes, watch me watching you. Your lips parted, sharp breath. Harder grip.
JOHN: Show me how to touch you, teach me what you like.
JOHN: Faster now, breath harder, harder, held. Spilling through your fingers.
JOHN: Let me lick you clean.
Ten minutes later, Sherlock's theatrical, if a little disheveled - shirt un-tucked and buttoned incorrectly - entrance lacks an audience. For the last twenty two minutes John has been in The Red Lion watching Chelsea crucify Arsenal in the London derby.