After losing a fight for the throne, Zhong Wan was exiled with his young masters. To survive, he relied on the acquaintance that existed between him and Yu Ziyou when they were young. He had some of Yu's personal belongings to show off, while making hints about an intimate relationship between them. Given the Yu clan’s powerful presence in the imperial court, the pretend relationship allowed Zhong Wan to live more comfortably. And over time, the stories he cooked up began to become more extravagant.
As rumors of their romance spread, it even reached the capital, where Yu Ziyou caught wind of his supposed epic love affair. The tales were so entrancing that Yu Ziyou, who had been hearing them for seven years, started to believe in them. He figured something special really did happen between them way back when…
(Source: Bilibili, translated)