欢笑背后的泪雨过天边的彩
[huān xiào bèi hòu de lèi yŭ guò tiān biān de căi]
This nickname contrasts laughter with hidden tears, suggesting the person has a complex life where not everything is as it seems. The second part '雨过天边的彩' (a rainbow after the rain) can symbolize hope and beauty emerging from sadness or trials.