Chapter 1

"Mom, Uncle Dan, I got accepted into the study abroad program in Florence!" Skylar announced quietly in the living room of their Upper East Side apartment, her voice as gentle as a ripple on still water.

Her mother, curled up on the leather sofa, lit up with excitement. "You got in? When do you leave for Italy?"

"In ten days."

Her mother hadn't expected such a rushed timeline. While excited, worry lines creased her forehead. "I'll help you pack everything. Since this is your first time in Europe, especially Italy, I reached out to Patricia - you remember my old sorority sister? Her son is doing his master's in Florence. You can reach out to him if you need anything. And don't feel awkward about it – you two were actually promised to each other when you were kids, back when our families were close. If you hit it off, great. If not, at least you'll have a friend there."

Skylar nodded absently, fiddling with the acceptance letter. "Sure, Mom."

Her mother looked surprised at her easy agreement. "Skylar, honey... you're okay with this? Does this mean you and your boyfriend... finally broke up?"

Skylar fell silent, her fingers stilling on the paper.

Uncle Dan immediately caught on, slamming his hand on the coffee table. "That guy never even showed his face at our holiday dinners – clearly wasn't serious about you. Good riddance!"

"Boyfriend? What boyfriend?"

A sharp voice cut through the room's heavy atmosphere.

All three turned to see Callias standing in the doorway.

He stood there in a crisp black shirt and tailored slacks, his presence commanding the room with an innate grace that spoke of old money and prep school polish.

Skylar trembled slightly as she stood. "Brother."

Callias responded with a meaningful "hmm," tossed his car keys in the crystal bowl by the door, and headed upstairs.

That evening, their mother prepared a feast and opened a bottle of aged Chianti.

She raised her glass, beaming at her family, ready to announce the news. "Come, let's celebrate together. Skylar is about to—"

Sensing danger, Skylar quickly interrupted, "Mom, this wine tastes off. Maybe we should open another bottle?"

Her mother looked puzzled – the wine was perfectly fine. But Skylar had already pulled her into the kitchen under the pretense of selecting a new bottle.

"Mom, please don't tell Callias about Florence yet."

Her mother found this strange at first. But thinking of how protective her stepson had always been of his sister, she understood their close sibling bond and agreed.

After picking at her dinner, Skylar retreated to her room upstairs. She showered and lay in bed, slowly drifting off to sleep beneath her down comforter.

At midnight, right on schedule, someone joined her.

Hot breath fell on her neck, followed by soft lips grazing and nipping at her skin. The cool sensation fully woke Skylar from her drowsy state.

She stiffened, instinctively pushing him away. "Callias!"

"So, mom's little matchmaking with some Italian grad student has you pushing me away now?" In the darkness, Callias's lips curved into a smile that didn't reach his eyes, his voice dangerously soft. "What was I then? Just a convenient fuck all these years?"

Skylar knew he'd misunderstood but didn't explain.

Callias's expression darkened in the silence.

He pulled her close. "Skylar, haven't I told you? No boyfriends. You're mine alone."

Feeling his heat against her back, Skylar wanted to avoid an argument. She lied: "It's my time of the month. I don't feel well."

Hearing her soft excuse, Callias's expression softened, though he frowned."Wasn't your cycle just last week? Running out of excuses, baby?" His tone softened slightly, though his grip remained firm. "But I won't force you. Not tonight. Get some sleep."

He held her tightly in his arms.

Listening to his steady breathing beside her ear, she lay awake.

No one knew that her boyfriend was her brother, Callias!

At twelve, when her mother remarried into the wealthy Harrison family, she and Callias, their only son, became step-siblings.

At fourteen, she called him brother, he called her sister – the picture of sibling harmony to their private school classmates and socialite circles.

At eighteen, he found her diary filled with secret confessions of love. He lounged against her desk, smiling as he read it over and over, then caught her hand as she tried to snatch it back, planting a kiss on her blushing cheek.

At twenty, their first night together happened during a thunderstorm. After that, they became addicted to each other, unable to stop.

Siblings by day, secret lovers by night, hiding their passion from Manhattan's elite social circles.

Skylar had always been the perfect Upper East Side daughter - straight A's, charity committees, Junior League events. Her relationship with Callias was the only wild card she'd ever played.

She loved him so much that she didn't mind keeping their relationship hidden forever – they could elope to Europe someday, start fresh where no one knew them.

But these dreams shattered two weeks ago when she overheard his conversation at his private club.

It was pouring that day. She'd gone to bring him his forgotten umbrella, but just before opening the oak door to the members' lounge, she heard his friend's voice.

"Cal, what's your endgame with the stepmom's daughter? Thought you were just going to hit it and quit it? Why're you still stringing her along?"

"Yeah, weren't you just getting back at her mom for marrying into your family? Don't tell me you've actually caught feelings."

Revenge?

Their relationship wasn't about love – it was revenge!

Skylar's face drained of color. Her mind went blank, her body trembling, but she stubbornly stayed to hear Callias's response.

Then his cold, cruel voice reached her ears.

"The longer the game, the sweeter the payback, isn't it?"

The room erupted in laughter while she stood frozen outside, her world crashing down.

So he never loved her. Dating her, calling her his, their passionate nights together – it was all revenge for her mother taking his mother's place in the family?

Her mother still had to live in the Harrison household. She couldn't let this become fodder for the society gossip columns.

After much thought, her only escape route was Florence – leaving Manhattan, leaving him.

Now, only ten days remained before she would disappear into the Italian countryside.

Looking at the countdown on her phone, Skylar removed Callias's arm from her waist.

Minutes later, he embraced her again. Each time she moved away, he unconsciously drew closer.

Her patience wore thin with this back and forth. Finally, she placed a pillow between them.

This time, he stayed put.

Skylar found her peace at last.

She knew their story would soon reach its end.

She would no longer belong to him, no longer be his dirty little secret.

Chapter 2

The alarm chimed at eight AM sharp, pulling Skylar from her dreams.

Opening her eyes, she found the space beside her empty.

To avoid their parents' discovery, they'd kept to their routine for five years: Callias would come at midnight and leave promptly at five AM.

Soon, they'd just be siblings again. He wouldn't need these secret visits anymore.

After changing, she went downstairs and immediately noticed an unfamiliar woman sitting on the sofa.

Her mother waved her over enthusiastically. "Skylar, come meet Callie's girlfriend! Be a dear and get her some water."

Victoria Silver stood up gracefully, extending her hand with a warm smile. "You must be Callias's sister! I've heard so much about you from him."

Skylar's hands trembled slightly. She glanced at Callias but said nothing, turning instead to get the water.

As she poured a glass in the kitchen, Callias appeared behind her.

He wrapped his arms around her waist, leaning down to kiss her.

Skylar quickly turned away. "Stop it. Your girlfriend's right outside."

Callias raised an eyebrow, stealing a quick kiss anyway. "Jealous? Sorry I forgot to mention - she's just my childhood friend who's been abroad. She just got back. Dad's been pushing the marriage thing hard, so I asked her to play along. Keeps him off my back."

"You know who my real girlfriend is, don't you?" he murmured against her ear.

Skylar listened silently, her face expressionless as she gave a noncommittal nod.

Her indifference caught Callias off guard.

He'd expected another jealous episode.

Usually, even just catching a glimpse of a love letter from another girl would send her into a spiral of tears and silent treatment.

When he'd confront her about it, she'd clam up, making him work for every admission of jealousy.

Deep down, she'd always believed their forbidden relationship could never survive in the light of day. She could never stand openly by his side as his girlfriend.

So instead of confronting him, instead of getting angry, she'd hide under her covers and sulk alone.

This time, faced with the same scenario, her reaction was suspiciously calm.

As Callias opened his mouth to question her, Skylar slipped past him with the water glass.

At breakfast, everyone took their usual seats.

Victoria was placed next to Callias.

They chatted and laughed about childhood memories, looking every bit the perfect couple.

Learning that Victoria had developed a taste for soft-boiled eggs during her years abroad, Callias placed his onto her plate.

She responded with shy delight, offering him a bite of her own egg.

Callias glanced at Skylar.

She kept her head down, focused on her oatmeal, seemingly oblivious to their exchange.

When she finally looked up to grab a napkin, he deliberately took a bite of Victoria's egg.

Skylar watched silently, then stood up from the table without a word.

Seeing her about to leave, Victoria quickly called out, "Skylar, are you heading out? Callias and I are going on a date - wait up, we can all go together!"

Skylar was about to decline when Uncle Dan spoke up.

"Come on, sweetheart - it's pouring out there. I'd feel much better if Callias drove you. You know how crazy Manhattan drivers get in the rain." His tone carried that familiar parental worry that brooked no argument.

With Uncle Dan's word given, Skylar had no choice but to head to the garage.

She needed to go to the visa office - now Callias would find out about Italy.

After considering her options, she resigned herself to the inevitable.

Let him find out. Her plans were set; there was nothing he could do about it now.

Minutes later, the couple joined her.

Surprisingly, Victoria chose the back seat, trying to engage Skylar in conversation.

Skylar responded with minimal enthusiasm.

As they drove through the rain, Victoria leaned close to Skylar's ear, her voice dropping to a whisper.

"I know you don't like me, and I know your relationship with Callias isn't just sibling love. But you two can never have a real future. He has feelings for me too, you know. Want to bet I could take him from you if I really tried?"

Chapter 3

Skylar's heart skipped a beat. She glanced at Victoria, who met her gaze with a smirk while pulling out her phone and setting a timer.

A minute later, right on cue, the alarm rang.

Victoria pretended to answer a call, quickly working up tears. She turned to the front seat, her voice trembling.

"Cal, the housekeeper just called - my puppy's really sick. I'm so worried. Could you take me home now?"

Callias pulled over, frowning at the relentless rain. When he turned back and saw her tear-streaked face, he hesitated before shifting his gaze to Skylar.

"I need to take Victoria to the West Side. It's out of the way - you should grab an Uber from here."

Victoria quickly thrust an umbrella at Skylar, not giving her a chance to refuse.

Skylar's eyes moved between them before she wordlessly opened the car door.

Rain seeped through the broken umbrella, quickly soaking her clothes.

The downpour was too heavy for any rideshare to spot her. She had to run, using her bag as makeshift cover.

After thirty miserable minutes, she finally reached the visa office, drenched and disheveled.

With her paperwork done and still no ride in sight, Skylar had to walk another hour home in the rain.

By the time she made it back, fever burned through her. She collapsed onto her bed, dizzy and aching.

Her dreams were dark and strange, her body damp with cold sweat as she fled from shadowy monsters.

When she finally forced her eyes open, she realized the monster was Callias.

He held her in his arms, spooning medicine between her lips. His voice was gentle, tinged with worry. "There you go, baby. Take your medicine. You'll feel better soon."

Skylar couldn't tell if this was reality or another fever dream.

She swallowed the medicine before drifting off again.

When she next woke, her fever had broken.

She instinctively reached beside her.

Empty.

Only his phone buzzed insistently on the nightstand.

She picked it up to find his friends tagging him in their group chat.

"Cal, you're one hell of an actor - dropping a multi-million dollar deal just to rush home when your little stepsister got sick?"

"Guys, I think he's actually caught feelings. Running every red light to get back to her? That's not acting."

"Agreed. No one gets that worked up unless they're in deep."

At the bottom, Callias had replied just once:

"Love her? I'd rather die. I'm just playing my part. The more she believes it, the more it'll destroy her when she learns the truth. Isn't that the point?"

Each word made Skylar's heart freeze.

Five years together, and all she got was "I'd rather die than love her."

Callias, you heartless bastard.

She felt her strength drain away, her hand dropping limply.

The bedroom door opened.

Callias walked in with hot water, his face changing when he saw the phone. He quickly snatched it away.

His usually lazy drawl carried a hint of tension. "What did you see?"

Skylar lowered her head, hiding her reddened eyes. Her voice was rough: "Was there something I wasn't supposed to see?"

She couldn't understand. If he knew how deeply she'd fallen for him, why didn't he stop?

Why drag out this charade so long?

Still being careful, still afraid she'd discover the truth.

Wasn't he tired of pretending all this time?

Enough! He'd won! She was already broken beyond repair!

Oblivious to her thoughts, Callias assumed she was just emotional from being sick. He quickly pulled her into his arms, soothing her. "No, baby, I was just planning a surprise for you. Since you're upset, I'll tell you early, okay?"

"I found out Denmark allows marriage between step-siblings. We could move there, make it official. I'm already working on the details."

They'd had this conversation countless times on endless nights before.

Now, hearing it again, Skylar felt nothing but a dead calm where her heart used to race.

She knew there was no future for them anymore.

In ten days, Callias's life would no longer include Skylar.

And hers would no longer include him.