Martin Freeman (the strapping gentleman who plays John) used to be on a comedy called Bruiser where he did a skit called 'over thinker'.

Here is the link, note that it would be best that you watched the skit before reading- .com/watch?v=N5nMzrSkmIg. This is where the idea for the story came from.

The doors to a shipping warehouse on the boundaries of the world famous city of London were swarmed with people. It was unusual, yes, since the place did have that unappealing fish smell to it but tonight it was a hotspot for the Metropolitan Police force. The grubby building was dolled up with the whole shebang: patrol cars, photographers, markers and more police tape you could poke a stick at. The only thing that was missing was the genius consulting detective and his partner. Surprisingly, Anderson was the first one to notice.

"Hey, I don't think anyone has insulted my intelligence since we got here. That prick must have thought himself too big to show up tonight" The officer muttered, crouching over a rather large man with his skull bashed in.

"Or maybe he is off starting his own blood bath…" Sally added from the other end of the body.

Lestrade rolled his eyes as he checked his phone. Sometimes he felt more like a grandad keeping his grandchildren from fighting amongst each rather than a DI. The same message still blared up at him from his mobiles screen; I'm on my way –SH.

As if on cue, Sherlock Holmes and John Watson strolled onto the crime scene. The other policemen parted as the couple strutted through the police tape like celebrities on the red carpet, dragging in all the stares of admiration. Anderson made a small puking sound.

"A murder. How exciting" Sherlock grinned broadly to himself, clasping his hands together.

"Yeah, only you would be excited about another person's death" Sally spat, attempting to make Sherlock feel remorseful, which obviously failed.

"It's good to see him excited about something" John said with a cheerful note. "I was down to my last resort for getting him off the couch" Sally gave the blonde man a funny look.

'Oh god…' John thought. 'She is giving me that look. She definitely took that the wrong way. I might as well have said I had to snog him to get him to move off that blasted couch!' John rocked uneasily on his heels. 'Just play it off, pretend I didn't say that last bit.'

John took a few nervous steps back as Sherlock crouched over by the head, his hands pressed together and tucked under his lips. John glanced around and acted uninterested, filling out all the awkward criteria of 'how not to make awkward eye contact with the person you just said something sexually misleading to'.

"John" Sherlock spoke again. Watson jumped a little at the sound of the detective's voice. "What does this look like to you?"

"What?" John asked.

Sherlock groaned in frustration. He reached up and wrapped his long spider like fingers around John's wrist and pulled him down to crouch unbelievably close to him. "This abrasion to the back of his spine, what can you tell me?" The detective asked again, striking his finger at the bloody mess before them.

"Well… it's… ahh" John stuttered. 'They probably think Sherlock's trying to get me to snuggle up to his cheekbones… which are rather quite large…' Sherlock's face snapped up to John's, their noses just missing collision. 'Oh shit! I'm looking again and I caught his eye! Quickly, just say something that will get them thinking about something else.'
Because of the pattern, the victim must have been hit repeatedly with a heavy object that was also long enough to splinter his spine and crush his skull" John blurted. Sherlock probably already knew this information but he used it none the less. He leapt to his feet and swept around to the other side of the body, his eyes sweeping the room.

"Where would there be a weapon like that in this kind of place…?" Sherlock said, off in his mind castle. John had barely got back on his feet when Sherlock hurled his phone towards him.

"I want you to send a text to Mrs Hudson. Tell her to prepare my riding crop for when we get home"

'Bollox. Why the riding crop? Now everyone is getting the mental image of us spanking each other erotically with a riding crop! That bastard!' John cursed. He pressed his thumb down on the 'on' button and the screen came to life. John let out a choking sound as the screen saver was the picture that Irene took of Sherlock wearing nothing but a sheet. Anderson and Sally peered around John's hands to catch a glimpse of what he suddenly became so tense about it. They not-so-subtly looked away, trying their best to keep from laughing.

'What should I do?' John thought in panic. 'Err… keep looking ahead. No, everyone will think I am trying to hard not to look, that I must be looking' Sherlock marched over to John's side, looking down over his shoulder. 'Damn. He's seen me see what he has as a screen saver! He thinks I'm picturing him in it! Him in just that thin white bed sheet, sitting in his bedroom looking all glistening and innocent. He thinks that I am just a dirty perverted man, oh what am I going to do!'

"Hurry up, John" Sherlock grunted. The detective slithered his arms around John's shoulders, pulling his flatmate to him. John caught his breath as Sherlock's hands met his as he grabbed for the phone. That was when John snapped. He ripped himself free from Sherlock and threw his hands up into the air.