Answer:
Here are some witty combacks that I found on some websites:
1. Can I ignore you some other time?
2. If ignorance is a bliss, you must be the happiest person alive.
3. So why don't you freeze your teeth and take your tongue down for a sleigh ride?
4. Let me guess- Home schooled?
Fell free to add more witty comebacks. And by the way, yo mamma jokes aren't considered as wittycomebacks so don't put any yo mamma jokes on this answer.