The same, however, cannot be said about Sherlock Holmes. His sartorial choices are as much about making an impression as they are about keeping him warm and decent. He lives for fitted shirts and finely cut suits. Even his loungewear is extravagant by most standards. It would stand to reason then, that what he wears under his clothes is bound to be equally fine.
He favours looser pants than his flatmate, but still slim and fitted enough not to cause wrinkles under his well-tailored trousers. His collection of undergarments bears remarkable similarities to his assortment of button-downs – white pairs with thin pinstripes, a soft dove grey, and even a silk pair in rich deep shades of plum. He knows how well those particular ones set off his pale skin, and has often used them to his advantage.
When he first had the pleasure of stripping John down on his bed, he caught himself smiling at the shorter man's choice of pants. Of course he'd wear sensible, solid briefs, they suited him well. He'd also noticed the appreciative gaze the doctor gave his own extravagant undergarments.
Sherlock catches himself humming slightly as he pulls open his armoire. While he was out Christmas shopping, he'd bought something for himself he knew John would appreciate - one new pair of deep red silk boxers.