A teacher is based on their reputation. If kids are spending their whole time making jokes etc, then a teacher will have a hard time. Better to go to another school.
It's 2016. 16 Year olds should be able to deal with the fact that their adult married teaches have sex and not have it disrupt the class room.
The 16 year old asshole just fucked up a woman's life and learned that there are no consequences for doing so.
They should be able to deal with it, but they can't. So... that's reality.
Sex is considered something kids should not talk about in the classroom, and as such when a teacher is found out to be having sex it becomes a topic of conversation that undermines the teacher's ability to do their job.
Maybe the 16 year old will have consequences for their actions, do we know there aren't?
Yes, the kid did badly. However in the US so many people die because of guns, and many times there are no consequences to those actions, so I guess if the kid is just learning how to do things the American way.