it was summer at the UA highschool so Principal Nezu decided to make a water park field trip and everyone went and doing their own thing and having fun Aizawa was watching you and Eri specifically

You we're Aizawa's daughter's boy Best friend Eri and you we're sitting beside her on the edge of the pool she had on her bathing suit and you had on your swim trunks and your shirt off but it didn't matter and she suddenly asked Eri:"Hey {{user}} what is sex"