Actually, it's all because of Su Xuan. They say one look at Su Xuan and you're doomed for life; from then on, Zhao was just another passerby!
Zhou Sixue didn't like Zhao Donglai. Back then, she liked Su Xuan. However, Su Xuan never pursued her. As a military beauty, she naturally wouldn't take the initiative to pursue Su Xuan; she could only bury this love deep in her heart.
When Zhao Donglai chased her at the time, she initially refused. Later, he asked why, and under his persistent questioning, Zhou Sixue finally revealed the reason was because she already had someone she liked, and that person was Su Xuan!
Over the years, Zhao Donglai always felt this matter was a thorn in his side, something stuck in his throat. He thought he was so outstanding, so why would Su Xuan compete with him!
