Special thanks to my daughter, SecretMoustache2, for suggesting John's special word.
Disclaimer: I don't own, 'cause if I did I'm sure my daughter would steal them from me!
At first it was just a sneeze or two and John pushed it to the back of his mind, blaming the dust in the archives at Scotland Yard.
When the sneezing progressed to a hacking cough, he sat down wearily on his chair and wondered why it was that Sherlock always asked him to trawl through dusty records (and more to the point, why he always agreed to it), when they both knew he would end up with a headache, sore throat, and feeling irritable.
In the cab home however, he started to feel chilly, yet when he briefly wiped at his forehead with the back of his hand, he was sure he felt hot.
By the time he reached the flat he was feeling so sorry for himself that he dragged the duvet off the bed, made a cup of tea, and settled down in a nest of eiderdown and rich cotton.
John must have fallen deeply asleep, because the next thing he knew he was lying in Sherlock's lap, being held tightly. He looked up blearily.
"Shnerougls." His mouth and throat felt like sandpaper.
"Pardon?" Sherlock frowned.
The blond doctor wriggled and squirmed deeper into the other man's embrace.
"Sheruggles." He said with a sleepy smile.
And Sherlock knew, for certain, that this was truly where his John belonged.