More than that, he's a teacher. He chose to enter a profession where he interacts with children all day. If you can't handle some ribbing then get another profession.

I doubt the girl is even antiemetic, the teacher provided pressure point so she pushed on it. When he reacted, she kept pushing.

He is supposed to be the mature on in the room. If he didn't carry on like a child himself, she would have dropped it and moved on.