Irritatingly enough, Sherlock had recently discovered he now had two weaknesses.
First and foremost, there was John. That was his biggest weakness. But that wasn't quite right; when John was around, Sherlock was calmer, more tolerable. When he praised Sherlock, Sherlock positively glowed! When he was in trouble, Sherlock was faster, smarter, stronger, better, whatever it took to help John.
But then there was the down side. When John was angry or upset, Sherlock hated himself. When John was gone, Sherlock was panicked and all trembly. When John was out with someone else, Sherlock was restless and moody grouchy beyond high heaven.
That's were weakness number two came in.
Comfort eating.
Granted, it wasn't life changing or anything sinister, but it still affected Sherlock in negative ways. It made him feel sluggish and slobby and slow. But god damn it, it worked! It brought Sherlock comfort when nothing else would. It made him feel like he was still in control of something. The salt-and-vinegar crisps wouldn't leave him alone and depressed in the flat. The triple chocolate cookies wouldn't go gallivanting off without him.
So when John went out with Sarah for the third consecutive night that week, Sherlock went to Tesco and bought a packet of cheese slices. And Sherlock spent the evening on his laptop, every now and then reaching into the packet, pulling out a slice, peeling off its plastic wrapping and folding the whole slice into his mouth. He continued like this until the packet was gone. Then he quickly stuffed the evidence into the bin and headed off to bed. No point staying up if there's no case and no John.
When John was in hospital after a case that ended particularly violently, (the criminal attacked John... so Sherlock almost killed the criminal) he nipped to the bakery across the road for three slices of vanilla cheesecake (all for himself) and a plastic fork. That evening was spent sitting by John's bedside while he slept, eating and watching until the cake was gone. For the duration of John's stay in hospital, that evening was repeated four more times with cookie dough ice cream, beef jerky, apple pie and a huge quiche lorrain.
By the time John finally got out of hospital, Sherlock found that he could only just fasten his trousers.
One particularly dreary evening (John had gone out with Sarah and told Sherlock not to expect him home 'til morning) Sherlock discovered that the corner shop down the road sold massive "to share" bags of Smarties. So he bought five.
Three bags of Smarties, five crap crime shows and a seriously tedious James Bond film later, at about half past midnight, he heard footfalls on the stairs. Sherlock scrabbled to hide the empty Smartie bags and pick up the closest book. John looked tired as he entered the flat and he threw himself down on the couch next to Sherlock. Sherlock noticed the distinct lack in the smell of woman's perfume on John. "I thought you wouldn't be back until morning?" Sherlock asked. John sighed. "So did I. But then she said something and we got into a fight and I left. And now I'm here," he said, no remorse in his voice.
Sherlock looked at John for a moment. "What did she say?" he asked in a small voice. John sighed again. Sherlock hated that sigh. That sigh said 'disappointed'. "She said you were a freak. She said that you were dangerous and being close to you meant I was only going to get myself hurt. And I told her she was wrong but she insisted that you didn't care about me at all. I told her if she cared about me at all she would stop insulting my friend. But she carried on. And then she told me I was an idiot if I thought you were actually my friend. And I told her i was an idiot for thinking she was the kind of person I wanted to be around. And then I walked out."
Sherlock looked at John. "You did that because of me?" He asked. John smiled a small smile. "Of course. The only person who's allowed to be mean to you is me," he said with humour in his eyes.
John reached over to the coffee table and picked up the fourth bag of Smarties. "This is your secret is it then? Smarties?" He chuckled. Sherlock looked furrowed his brow, frowning slightly. "Smarties, smart, you? Get it?" Sherlock let himself smile slightly. "Very good," he said as John took a handful of the multi coloured confection.
They stayed like that for the rest of the night until they both fell asleep, John leaning slightly on Sherlock's arm. Sherlock hadn't needed to touch the chocolate for the rest of the week. Or any other comfort food, for that matter.