座位留着大姨妈最鲜艳床单留着大姨夫最透剔
[zuò wèi liú zhe dà yí mā zuì xiān yàn chuáng dān liú zhe dà yí fū zuì tòu tī]
This nickname literally refers to menstruation with slang terms used ('大姨妈/DaYiMa': Aunt menstrual period, '大姨夫/DaYiFu': Uncle blood stain on the bedsheets), presenting a very casual attitude towards discussing menstrual hygiene. This nickname might belong to users seeking to challenge taboos around discussing menstruation freely without shame, also hinting at adult themes indirectly.