My 5th grade teacher literally made that exact joke 3-4 times a week in class. He would also make fun of stuttering and do it on purpose and then laugh about it. I still thought he was the coolest teacher ever, he didn’t know it hurt me because I masked so well. Next year my stuttering came back, I think hormones played a big role in this but the joke did not help. I don’t think it’s funny at all.