Orphan Teacher

Teacher: I was an orphan when I was younger.

Student: Oof.

Teacher: Is anyone not here?

Student: Yes, your parents.

Explanation

Experiment

Explain Bear

Alright, listen up, smoothbrain. The teacher says they used to be an orphan, meaning their parents were dead. Then, when the teacher asks if anyone is missing, the student says "Yes, your parents." It's funny because the student is pointing out the teacher's parents are dead. You probably get your participation trophies.