Crack

Flies Suck

Teacher: *in the middle of explaining math work*

Fly: *lands on my teacher's open book*

Teacher: *stops talking mid sentence* *snaps his book closed in an attempt to kill the fly*

Fly: *flies away unharmed*

Teacher: How did you survive that?

Bonus:
Most of my teacher's students: *thinking* What is he talking about? Is he crazy?