Chapter Text
Gon hadn't been aware enough to notice when he fell for Killua, but prior experience and an older heart made him keenly aware of his fall for Alluka.
Gon had never really had any siblings, after all, certainly any younger ones, and while Killua was halfway between brother and....well, and something else, something he couldn't quite think about yet,
Alluka was...
Alluka was the day she'd wanted to go on the roller coaster at the fair, but Killua hadn't let her, so Gon had waited until Killua turned his back. Then he'd whispered in Alluka's ear, grinning and devilish, giving her the last few cheat codes to get pretty much whatever she wants. Gon had always been good at having his way with Killua, and it was nice to have a cohort to which he could pass his knowledge on.
That was how, when Killua felt Gon's touch on his shoulder, he'd had to look DOWN at him for once, met with not only Alluka's pleading puppy dog eyes, but also Gon, damnable ass Gon, who was resting his chin right on Alluka's head, and he ALSO had the puppy dog eyes and auuuughhhhh and jesus christ this was so obviously on purpose.
He turned away before he melted on the spot, but only just. “Tsk,” he said, the old defense even more transparent on his lips than usual. “Fine, do whatever you want. I'm not making you feel better if you barf, though” he'd said. Alluka turned as Gon drew back, and they were grinning at each other, and while Gon didn't look away from Alluka, he knew Killua well enough to know the way he turned his eye back to look at them from the side, as if hoping they wouldn't notice he was hiding a smile.
They'd gone on the ride, alright, and they'd both gotten sick and whined at Killua for a good twenty minutes after, but that moment when Alluka threw her arms around him and squealed thanks had been the absolute best part.
Well....almost.
At the time, he thought about how nice it would've been if he'd had a little sister like that. How lucky Killua was. So once the sick had passed, and they were ready to move on to the next ride or game, Killua telling them he'd told them so all the while,
The best part came when he felt a small hand slip into his, almost shyly. He'd looked down to see Alluka, blushing a little but not quite shy. “Thank you....” she said again, trailing off like she'd had a thought that distracted her.
“Hehe, it's no problem! Getting my way with Killua is always fun” he freely admitted. He heard Killua Tch again as he turned backwards to look at them, and caught his sight lock onto their intertwined hands. Noticing that had distracted him enough that he hadn't been even a little ready for what came next.
“Um....calling you Gon doesn't really feel right.” She admitted. He was still mostly looking at Killua when he heard:
“Big brother's the only big brother for me, so instead...can I call you big bro, instead?” She asked. Gon's neck snapped back towards her like a whip crack. It was pretty hard to really shock Gon, but here he was.
He looked down at her, all eyes and questioning. She looked worried, as if he'd deny her request and also run away or call her a name or something. Dimly, almost more feeling than thought, he processed that he understood why Killua turned away from him all the time, for once.
But turning away wasn't in Gon's nature, and he wasn't about to start. He smiled at her, as big as he'd ever smiled at Killua, and was responded
“Yeah! I'd be really happy if you called me that!”
When Killua smiled, Gon thought, it was like the whole world narrowed to a point around him. Everything went tunnel-visioned, until all he could see that he cared about was the curl of his lips, the soft and half-hearted defense in the way he turned away his eyes. When Killua smiled, it was like he was taking all the light the world could possibly have and hoarding it in himself. Like everything Gon could think of that was worth having was locked inside.
When Alluka smiled, then, it had the inverse effect. Alluka's smile lit up everything: Her face, the colors of her clothes, the pigment of his own sun-beaten skin. When he looked over at Killua, eyes wide and a small o in his lips, Gon thought that as impossible as it was, even he looked brighter.
He understood now. Killua's eyes seemed to be watering a little bit, and he turned his face away from them again. Gon thought he might cry, too, just from the things Killua had told him.
Who could have locked a girl like this up, to hide her away from everything? Gon didn't understand, but he also didn't dwell on it. He had already decided that today wasn't for getting mad.
Today was for making Killua happy, and now...
today was for making her happy.
His new little sister.
He grinned, and he was pretty sure he'd never smiled this hard in his life.
He looked at Killua. His shoulders were heaving a little bit, but he had grown long, delicate and lithe over the last couple of years. He was composed and put together, even when he cried. He'd have time to clean up before they got there, if Gon gave him prior warning.
“Come on, let's catch up to Killua!” he said loudly, picking up the pace through their interlocked hands.
Some part of him might have thought he should give Killua a little more time, let him sink in the moment for a little while longer, but Gon Freecs was selfish by nature, and there was little on his mind except for how badly he wanted to be holding that second hand.
Though he had a feeling he and Alluka were going to have to start taking turns, now.