与一只蝶不期而遇与一个人一见钟情
[yŭ yī zhĭ dié bù qī ér yù yŭ yī gè rén yī jiàn zhōng qíng]
Encountering a butterfly by accident and falling in love with someone at first sight, this nickname encapsulates the idea of serendipity and immediate attraction or romance that starts unexpectedly and blossoms instantly.