你那个鲜艳的大姨妈
[nĭ nèi gè xiān yàn de dà yí mā]
This unusual and colloquial term humorously references menstruation using familial slang (大姨妈 translates loosely as “Aunt Flow”). Here it may convey lively, vibrant presence or mood swings related to this context, used perhaps in jest among friends familiar with this culturally-specific euphemism.