Copy-Paste Comeback

When you insult someone because they're stupid, and they write or say the exact or almost exact thing back.

(What a conversation with a person who uses copy-paste comebacks looks like.)
You: Hey, what do you want on the pizza?
Stupid Person: Pineapple.
You: Ew, heck no. That's disgusting.
Stupid Person: No, you're disgusting.