Was the initial comment making fun of your stutter? If so, I’ve had that several times in life. When I was a young kid, I would walk away. As a teen, a simple fist to the face solved a lot. As an adult, if another adult makes fun of a disability then I feel sorry for them. I will engage another adult making fun of anybody, to their face or behind their back. If the comment was all in good fun, I would not say my comeback if I knew I was going to stutter. I don’t like butchering jokes