少年的心红不过大姨妈
[shăo nián de xīn hóng bù guò dà yí mā]
The nickname 'The Boy's Heart is Not Redder than Aunt Flow' implies lighthearted sarcasm towards intense emotions. In Chinese culture, 'Aunt Flow' (referring to menstruation) has red color which metaphorically overshadows even passionate young love here.