First, lotus nut is actually very kind and loyal, but when she overheard your wife tell Queen Jia that she was going to send maids to woo and find out about the emperor, Su Lian incited lotus nut. Finally, the queen also decided to let Lotus Heart go, especially Lotus Heart begged the queen not to let herself go. They even threatened their own families, and Lianxin had to agree. At this moment, Lian Xin was disheartened and hated the queen.
When he was dismissed by imperial secretary and insulted by Qin Wang, he couldn't bear it any longer and threw himself into the river. Fortunately, I was saved by Ruyi. After being rescued, he expressed his willingness to be loyal to Ruyi, and later used Qin Wang to help Ruyi clear his grievances, which also proved this point.
Second, lotus nut betrayed the queen three strokes:
The death of Prince Duan Hui was the result of Lotus Heart's help to Highland, because Highland knew that the Queen had hurt Ruyi, and this was to avenge her and let the Queen taste the sadness of losing her beloved son. It is not clearly pointed out in the play, but we can learn from several details of Lotus Heart's treatment of the second brother.
When the queen gave birth to the seventh brother during childbirth, Lotus Heart prevented the imperial secretary from inviting the emperor and the queen mother, apparently to avenge the queen. If the queen really died in childbirth at this time, Lotus Heart would be happier than anyone else.
In the latest story, when the queen fell into the water, Lian Xin clearly saw the queen struggling in the water, but she was indifferent and did not call others to save her.
To sum up, Lian Xin did betray the queen, but it was also the queen's own fault. If Su Lian insists on marrying Qin Wang, the ending may be really different. The little guy gives the protagonist a fatal blow at a critical moment.