All women in love may throw a tantrum for all sorts of bizarre reasons, most of which leave their boyfriends utterly confused. But at their core, these outbursts stem from a lack of security.
Forgetting birthdays, anniversaries, or the number of days since meeting her. Forgetting the things she likes.
Of course, they know these are trifles, but once they start thinking it means you don't love them, it becomes a big deal.
Li Xiaoyu's sense of security was no different, she didn't expect Tang Xian to actually fight for her in a bridal contest, but he at least needed to show he was willing.
Just as women ask men to reach for the moon, men know they can't do it, but must show their determination to accomplish the task.
After all, she doesn't really care about that particular moon.
Similarly, if she starts asking for a diamond ring or a house… sorry, that probably means she actually cares. If you can't afford it, you're done for.