But really, you might consider that you’re the only one who seems to be making a big deal out of this here.
Actually, mfm could have just said he chuckled and then everyone leave it at that. Your calling him out repeatedly for it seems to be what turned this into a big deal.
I mean, I certainly don’t remember ever coming close to finding humor in someone mocking a person who stutters, but ok.
You certainly participate in openly mocking people for other things here on this site. Other people laugh at times when you do it. The fact that it’s not related to a disability is irrelevant.