This is going to be unpopular, but if I got offended every time a girl smiled at my stutter I would have no girls like me. You stutter. People (girls, namely) are going to smile, they might even crack a joke. Don't treat it like they're trying to knock you down because once you show negativity they'll show negativity. What does seeing them uncomfortable even do for you? Nothing good, but if you want bad experiences and recurring negativity keep at it. You need to show people that you're comfortable with yourself. If every stutter is treated is a traumatic event where smiling isn't allowed then you'll never succeed socially and people will stay away. You need to lean into your condition.