Hey, it’s always good to be open about it rather than see it as something to be ashamed of. Just remember that it’s just one part of who you are and it shouldn’t have to be the only thing you are. Your friend clearly said they know you stutter, and obviously it hasn’t changed how they feel about wanting to be your friend. I’m curious what reaction you were looking for though. I think with people that don’t know you that well, they’d probably say “oh I didn’t even notice”, at least that’s what I’ve observed from when I’ve told acquaintances vs. close friends. I say that’s a good thing though!