大姨妈的妹妹要叫什么
[dà yí mā de mèi mèi yào jiào shén me]
This is a humorous or colloquial term used to express frustration, particularly in reference to menstruation. Literally asking 'what would the sister of a monthly visitor (Aunt Flo) be called?' The context can vary, but it generally conveys annoyance and exasperation.