大姨妈浸了整张床
[dà yí mā jìn le zhĕng zhāng chuáng]
This is still based on the previous explanation for '大姨妈' (periods). This one specifically talks about the embarrassing situation where menstrual bleeding leaks all over the bed sheets, again with a tone of sarcasm. The expression also indicates inconvenience and displeasure caused by menstrual cycles.