If they know about your stutter, they’re just being assholes. I had a friend once that heard me stutter and said “dang you’re still doing that? I thought you grew out of that!” I had to tell her it’s a real struggle for me everyday and as my friend she should know that. I told her to either accept me for who I am or I have no problem leaving her in the dust. I’m glad she valued our friendship over that because she’s never said anything about it ever again. Maybe express your concerns with them but I know it can be different for guys etc. You could always start a discord group or a gaming group on here for other people who stutter. I bet you’d be surprised who is interested. If nothing else it’d be a space for you all to talk freely, free of judgement. You deserve better.