The longer a premarital relationship lasts, the less impulsive it becomes. The more flaws are discovered, the greater the chance of a breakup, let alone marriage.
Therefore, the Prince does not intend to have much interaction with Si Motu before marriage, including everything she wants to do in the Mirror Country, which she does not want Si Motu to know.
Before Si Motu's impulsiveness ends, to become husband and wife and continue the bloodline of the Mirror Country until transitioning from lovers to family.
By then, there will be no need to hide her shortcomings.
The Prince doesn't believe in love; after all, the relationship between men and women is an illusion constructed by hormones, and this ephemeral thing cannot give her a sense of security.
She hopes to skip this stage and reach a family relationship with Si Motu.
If they become family, she won't worry about her shortcomings being intolerable, nor worry about losing him.
