I had a band teacher that I highly respected in high school. He took a band program that was the worst in the state, a complete shit show, and made it an award winning program. I always saw some of the students hanging out with him in his office at lunch, never thought about it my self or noticed that it was all girls. Fast forward a couple of years after I graduated, I'm working in a local popular sandwich shop down the road from the school. I always saw this one girl who would come in and get his lunch order. I asked her, and she said she was the student assistant for him. The school setup a program after I graduated to earn working experience as student assistants. It turns out the teacher was having an affair with this girl, who was only 17. The school district IT admin found explicit emails between them on the schools email system, and things went haywire. And since the law at the time in my state was 16 was the age of consent, it wasn't illegal. But it was still a huge scandal, married teacher sleeping with his student. The school forced him to resign and the girls family told him to never contact her or come near them. Once she graduated, they got married and are still married to this day.
The schools I know have specific rules of conduct that says anyone who works at the school can not have a relationship with a student, and also for two years after the student has graduated or left the school. And that’s apart from age of consent.
I'm all for age of consent, but considering that you can have graduates as old as 19-20, and teachers as young as 23-24, I have to admit it seems a bit strange to put restrictions on what they can do outside of (1) what is legal, and (2) what effects their job (like having a relationship with a current student, especially one that you teach).
Like, I know several people in my graduating high-school class that were with someone older than our youngest teacher, a couple of which are still together with the person 10 years later.