A Heartbeat Off Track [Not-Actually-Siblings]

Also titled The Rules of Crossing the Line. I'll start posting it once I've polished my writing a bit more.

★ Age gap | Powerful man falls hard | Stepsiblings who aren't related by blood | Brothers' battlefield | Forbidden tension

★ Refined scoundrel in power x outwardly obedient, inwardly wicked student

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Qin Chengyan detested his stepsister.

She relied on her beauty, which captivated countless men, to get away with anything.

She had even started dating his younger brother, Qin Yizhou, her other stepsibling on paper.

He had never been one to tolerate the slightest flaw, and he would never let a materialistic, shallow woman seduce someone from the Qin family.

Especially that restless hand of hers resting on Qin Yizhou. It was like a thorn in his heart, irritating him beyond words.

Qin Chengyan warned her coldly to her face, his tone leaving no room for argument.

"Lin Qinghe, Yizhou is your stepbrother. How dare you cross the line?"

-

Lin Qinghe thought her big brother was crazy.

Seriously ill, incurable, and beyond saving.

All she had done was entertain a few young men at a banquet out of politeness, and he came home with a cold face and scolded her.

Hey, she hated those high-society gatherings. Qin Chengyan was the one who insisted on bringing her.

At least her second brother was gentle and attentive, the complete opposite of the big brother she couldn't stand.

Ever since she learned that her big brother hated seeing the two of them being affectionate, she made a point of provoking him in front of his face.

She ended up taking the game too far, completely overlooking the growing possessiveness and jealousy in Qin Chengyan's eyes.

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Then one day...

Qin Chengyan lost control and pinned her against the study wall, his falling kisses nearly swallowing her whole.

Just beyond the door, Qin Yizhou was looking for her. His footsteps drew closer as he called her name.

Lin Qinghe struggled in a panic. "Qin Chengyan, you maniac! Let go of me!"

"What, afraid he'll find out?"

The man's Adam's apple bobbed violently. Beneath his shirt collar, kiss marks were smeared with the traces of their intimacy.

"When you were tangled up with me in bed until midnight yesterday, why weren't you afraid then?"

Reader's guide:

* One-on-one romance, both leads' first time, happy ending

* The heroine seems obedient but is rebellious to the core, with a big contrast between her two sides. In the early chapters, she gets caught up in a tug-of-war with both brothers.

* The big brother is a gloomy, obsessive type, and the second brother is no pushover either. They compete and fight over her.

* Blended family. There are no romantic feelings while their family ties remain in place, and the heroine and her brothers are never registered in the same household.

* Detailed content warnings will be in the author's note after Chapter One. Enjoy reading, mwah~

* Blurb written on September 14, 2025

Theme: You. Dare. Cross. The. Line.