English Teacher, during discussion of Thoreau's "Civil Disobedience": It's like how people toilet paper a house to attack the person who owns the house indirectly through the house.
Student: No, thats just for fun.
Teacher: You guys need to transcend.
Student: What, so we toilet pape the person?

In history:
Student giving presentation on whether the industrialists were captains of industry or robber barons: "Robber barons" isn't really negative, is it?
Teacher: Yes it is. That's why I put it that way. Robber barons. People that rob you. That's negative.

In math:
Teacher (drawing a shape on the board): Does that look parallel?
Class: Yes.
Student: That does not look parallel!
Teacher: Well, you know what I mean. Now I feel self-conscious about it.
Other student: Nice going, [first student].
First student (to teacher): Oh, you'll get over it!!!

Another teacher came into our physics class.
Physics teacher (to class): Lets say good afternoon, Mr. [Other teacher].
Class, in a monotone: Good afternoon, Mr. [Other teacher].
Physics teacher: Next time, with more enthusiasm.
Student: Next time, with more enthusiasm.
Other teacher, points at student and says sternly: We have places for people like you.