老师你大姨妈来了么

In Chinese internet slang, menstrual period ('Dàyímā') is sometimes referred to playfully and indirectly. This nickname may have come from an impudent and playful question asked to a female teacher; essentially making fun of a woman being in an irritable condition, which can also seem quite disrespectful. However, this sort of informal language should generally be avoided on formal social platforms or when communicating directly with elders or teachers.