In the early 60s (5th grade for me) my family moved to a rural community, but people in the music industry had found this small town and suddenly it was classified as the fastest growing community in the nation. Lots of new teachers and schools overcrowding. Beginning of the year there would be 30 kids on a school bus route, by the end of the school year there was over 150 kids riding that bus. Standing room only. Class rooms would grow from 25 to 70. If new teachers could be found classes would be split at mid term.
7th grade: I was the largest kid in the 7th grade. Over 6' well muscled from working summers on the farm. I was the most dominating boy in the class. I was not a bully, but no one messed with me either. We got a new teacher in. She was "hot". All the boys had a crush on her, me included. Half the way through the year she rented the house next door. I would see her occasionally and wave.
8th grade: The new teacher still lived next door, but I no longer had her as a teacher. But I started seeing her more often at her home. She started helping me with math. I was a big male, aggressive, and demanding. Yes, it happened, I was the one that initiated the relationship. She said later that I was so big, and dominating that she just could not say no. After about 6 months I started dating another girl and the teacher and I broke it off. No one ever knew, we kept our mouths shut.
9th grade: A new male teacher came in. First day he came over and sat down at the table I was sitting at in the cafateria during lunch. He let me know he had married the HOT little lady, and that she was OFF LIMITS from that day forward. Yea right, I was bigger than he was, what a challenge.
What I'm getting at is it happens more times than people know. Often started by the boy, like I did. When a teenage boy, with raging hormones, looks at a good looking small teacher, morality for him goes right out the window. She is the ultimate conquest, far more than any of the girls his own age. So I have never blamed the female teacher, the male is the one in control. I don't care what you guys say is right or wrong, that is the humane physiological makeup. More times than not Teaching, Morality, Religion, all take a back seat. It's the female submitting to the dominate male. It happens, and it is going to continue to happen as long as there are males and females.
I have discussed this with my son the biology major several times. He explains it by saying humans are herd animals, just like horses, deer, and other mammals. The females submit to the most dominate male. The biggest Bull gets all the cows, the toughest Stallion gets all the mares.