You're going to get a lot of hopeful, but naive answers from people that mean well, but are arguing about a perfect hypothetical world.

What will happen in the real world with immature kids, is that some kid will find the pornographic material of the teacher, send it to their classmates, and the class will then proceed to relentlessly mock the teacher. There will be no respect and the situation will become untenable. The school will then face the choice of having to disipline dozens of students for inappropriate behaviour, which could involve multiple expulsions depending on how far the mocking went, or the school fires one teacher. What choice do you think most schools would make in such a scenario? I'd pick disciplining all the students and expelling those that leaked the pornographic material, but we all know most schools would not do that.