The first time they played this game, Kurogane thought it was stupid.

The idea came from the twins, of course, and Kurogane would bet that Fai was the one who suggested it to his brother. He had a wicked smile plastered on his face when they approached Kurogane that day, Yuui following close behind. Kurogane had been prepared to deny whatever crazy request they had, but as they explained what they wanted, he couldn't bear the thought of wiping that hopeful look off their faces. He sighed, agreeing to play just this once, and the twins laughed and kissed him and dragged him to their bedroom.

That's how he ended up wearing a blindfold, kneeling on the bed as Fai and Yuui positioned themselves in front of him, careful not to make any noise so that Kurogane wouldn't be able to know who was who. He didn't understand why the twins wanted to do this - he usually had no trouble telling them apart, and he doubted doing so with a blindfold would be much of a challenge like they said it would. But he played along, tracing their bodies with his fingers and then his mouth, feeling them tense and squirm but stay silent. Kurogane could sense their smiles, identical, as he focused on their every reaction and tried to think of a way to get one of them to lose. After a while, when all of them were breathing heavily and Kurogane was about to rip the blindfold off and end that stupid game, his teeth grazed a wrist and there was a gasp, quickly silenced but enough for Kurogane to smile against the sensitive skin.

"Yuui", he whispered, surprised by how raspy his voice sounded. Hands pulled him up and his blindfold was taken off, but Kurogane barely had time to register the return of his vision before he was caught up in a desperate kiss.

"You win", Yuui said against his lips, and Fai laughed from where he'd moved behind Kurogane, leaning forward so that his breath was warm against the man's ear.

"But we will win next time."

Kurogane had been tempted to say that there wouldn't be a next time, but the twins' lips and hands were too distracting for words. It was a good thing that his answer was left unsaid, though, because in the next few months they would play that game many more times. They never planned it beforehand; Fai and Yuui would simply go to Kurogane with a blindfold in their hands, and he would let them tie it without complaining. Even when they were not playing, Kurogane found himself paying more attention to the twins' reactions, looking for sensitive spots and comitting them to memory, noticing how each of them reacted to his touches. There was a thrill not only in the challenge, but in realizing he was getting to know them better than he ever thought possible as he searched for different ways to guess each time.

It wasn't always something sexual. Sometimes Kurogane could recognize Yuui because he smelled of the cookies he'd spent the afternoon baking. Ever since he accidentaly found out Fai was ticklish, he'd guess it was him from the way his muscles tensed when he skimmed his fingers over his side. And even though Fai and Yuui did their best to make it hard for Kurogane to get it right, saying he wouldn't win next time, they seemed happy every time he did. They would always lie down afterwards, hugging in a tangle of limbs, and Kurogane would never get tired of watching the way they smiled. So identical, yet so different.

It was still a game, but Kurogane stopped thinking of it as stupid. It brought them closer, made their relationship stronger, and even if that wasn't what the twins had planned when they first suggested it, Kurogane couldn't complain about the way it turned out.

"You might have won this time, Kuro-pon, but we'll definitely win the next."

"We'll see."