Characters: Hikaru and Kaoru.
Word Count: 277.
It's just a matter of perspective, just like appreciating art. They're not really identical: Kaoru could probably give a list of every single detail that makes them different: they just give the illusion of being the same. Kaoru is more than okay with this: he'd much rather have all of them belive that they are the same. He knows Hikaru shares his feelings on the matter, even if they've never talked about it.
Even if they're not identical, they are two of a kind.
When they get inside a store, they pretend not to pay attention to anyone else there while they choose what they want to wear, until they've decided what they want, or what's the situation. There doesn't have to be a look, or a signal. Just after he has taken his shirt off - never mind going to one of the changing rooms - and he's sliding the shirt up his shoulders, Hikaru's hands are over his for a moment, and then there's the whisper of his body against his before taking the shirt and buttoning it carefully.
"Allow me, Kaoru." Hikaru says, looking into his eyes. Kaoru bends his knees enough to seem smaller, eyes wide in adoration while he blushes: he's an expert doing that. "I don't want anybody else but me seeing your skin."
There's the ever present sounds of girls sighing and some squealing. Kaoru pretends he can't hear them and he averts his eyes, shyly, twisting his hands over Hikaru's shirt.
"Hikaru... saying those things... and in public...!"
It's all a matter of perspective. The fun part is trying to understand other people perspective, and see how it changes.