When I was in HS back in the mid '70's the 23 year old shop teacher was dating a 16 year old female classmate. They were married about 2 months after she graduated and have been married since. Everyone new about their dating but it was kept guiet.
I also know for a fact a guy on my track team also had sex with our Spanish teacher because another student watched it...she was probably 30-35 years old at the time and divorced. She may have had others. She would have the male students at studyhall go home and cut her grass. She would leave the gas can and gas outside. Again mahny people knew about it but it was kept quiet.
Children aren't children forever. Some parents have to let them make their own decisions but live with consequences.