Prompt: paranoia
Issei and Ilya glared daggers at each other.
Shirou looked between them with a worried expression on his face. I kind of want to say that this is a natural result of their roles… he thought. But that's weird. What does that even mean, anyway?
Finally they turned their glares onto Shirou. "Emiya," Issei began, "just because this girl showed up out of nowhere one day and claimed to be your sister, doesn't mean you have to turn a blind eye to what she is! She is absolutely the most cruel, selfish little girl I've ever met. You can't possibly-"
"He's so mean to me!" Ilya sniffed, though by now Shirou could tell that the tears were fake. "And he's keeping you from spending more time with me. You don't really like him better than me, do you, Oniichan?"
"You don't really prefer this girl's company to mine, do you, Emiya?" Issei demanded.
Shirou shook his head frantically. "That's not true. I like you both the same," he said, hoping to appease them. "Okay?"
Both of them were silent for a moment.
"That's a wussy answer, Oniichan," Ilya said at last.
"Emiya is king of the wussy answer," Issei noted.
"He should really stop talking like that…" she mused. "Maybe we could train him out of it?"
"It sounds like a good idea. So, shall we become business partners?" he asked, looking at Ilya with newfound respect.
"We'll be business partners!" she agreed.
"Good. Now… Emiya!" Issei snapped. "From now on, state your answer clearly! Keep your chin up and shoulders set! There's no backing down!"
Ilya joined in. "Don't think about what the consequences will be! Speak your mind as soon as you hear the question!"
Shirou swallowed hard. What… what have I done?