How is that menstruation? She gave a stereotypical reply used in manga and anime when a girl is wet down there and embarrassed about it. Also, betting they get the call from the front informing them their time is running out and asking if they want to extend their stay. 50/50 on if they say they want to extend. If they do want to, betting they find they have no money for it and have to leave. No way this cock-tease is ever going to end unless its last chapter and after graduation and only implied.