Yeah, I've met lots of people who laughed out loud or said "forgot your name?" while I was in the middle of stuttering, but 95% of the time, it's out of surprise or they think I'm joking around. Then when I explain to them that I have a stutter, their face drops and you can just tell they feel super shitty about how they acted. I've met very few people who have outright mocked me out of malice.