The morning light streamed softly through the wide mansion windows. Charles and Jane moved through the house with the ease of a newly settled couple, gently waking Rosie and Arthur with warm smiles and polite wishes.
Rosie stirred slowly, the weight of the previous night settling like a rock in her chest. Her lips still tingled from the kiss. Her fingers still remembered the feel of Arthur's skin. Guilt twisted inside her, not just because of what had happened… but because she hadn't hated it.
After getting dressed, Rosie quietly made her way to Arthur's room. He was still in bed, half-asleep, but his eyes opened when she stepped in.
"Arthur…" she began, her voice soft but firm. "About last night… it shouldn't have happened."
He didn't say anything.
"It was just… in the moment. It doesn't mean anything. I want things to go back to normal. We pretend it never happened, okay?"
Arthur blinked slowly, the corner of his mouth twitching. "If that's what you want."
"I do," she lied.
"Hm," was all he replied, sitting up and rubbing his face as she turned and walked away.
At church later that morning, everything was calm — too calm. Charles held Jane's hand, whispering into her ear. They looked at peace, almost glowing. Rosie tried to focus on the sermon, on the stained glass, on anything except the warmth she felt when Arthur's hand accidentally brushed against hers on the bench.
It was just a touch.
But something about it lit a small fire inside both of them.
As the priest spoke of love, redemption, and connection, Arthur closed his eyes. He didn't pray often. But this time, he whispered something to whatever higher power might've been listening.
"Just let her be in my life. I don't care how. I'll change. I'll be better. Just let me have her."
And beside him, Rosie whispered her own plea.
"Let me forget last night. Let me erase it before it destroys everything."
But destiny, as always, had other plans.
After church, they all shared a warm brunch. Jane and Charles talked about upcoming work and laughed over wine, while Arthur picked lazily at his food. Rosie barely touched hers.
Eventually, everyone split — Charles and Jane left for work, Rosie headed to college, and Arthur returned home and collapsed into bed, exhaustion catching up with him.
At college, Rosie couldn't focus. Her notes were a blur. The professor's voice faded into background noise. Her mind spun with the memory of Arthur's lips, the way he'd looked at her, the danger of it all.
Was it wrong? Probably.
Did it feel wrong? Not really.
Back home, Arthur was lounging shirtless on the couch in nothing but his joggers when the doorbell rang. A few staff moved around, but he opened the door himself — and there stood Rosie, fresh from college, tired and slightly flustered.
He leaned against the doorframe. "Hey."
Her eyes flicked to his bare chest, then away just as quickly. "Hey… You good?"
"Surviving," he smirked. "You?"
Rosie walked in. "It was… a long day."
Arthur let her settle in. They shared snacks on the balcony. Laughed a little. Talked about nothing and everything.
"So… that party," she started, biting into a cookie.
He glanced at her. "Yeah?"
"It was crazy. But fun," she admitted. "I… I wouldn't mind another invite. Just maybe with less drugs and violence?"
He chuckled. "I'll try."
As they talked, their parents pulled up in the driveway below. Rosie and Arthur looked down from the gallery to see Charles and Jane stepping out of the car — and kissing, warmly, openly.
The sight caught them both off-guard.
Rosie turned away first, uneasy. Arthur followed her lead. That image — their parents in love — was a reminder of the boundary between them. But it didn't make the feelings disappear.
Later that night, Rosie, thinking he was asleep, changed in her room with the door halfway open. Arthur passed by and caught an unintentional glimpse of her back, the curve of her waist as she pulled on a loose t-shirt.
He froze.
Then quickly turned away, heart pounding in his chest, guilt and desire crashing together.
He knew he shouldn't feel this way.
But she wasn't his sister by blood.
And his heart… didn't care about the lines they weren't supposed to cross.