As a stutter myself, I tend to have to put way more inner thought when I’m stuck in a bad stretch of influency. It blocks my ability to alter my tone and make appropriate facial expressions naturally, and eye contact is hard to keep, etc. It’s hard to spontaneously laugh if something is funny if I’m hyper focused on trying to speak, almost like tunnel vision. I can’t speak for him personally, this is just my experience. I also tend to be very upfront about my stutter when I meet someone just to break the ice and prepare my audience to know what to expect, so again I can’t speak on the right timing to talk about it. I do think it’s awesome you’re here asking advice from others who stutter, many people would just jump to conclusions and just ditch out on what could be a great opportunity. As others said, maintain eye contact, don’t finish sentences, lean in and seem generally interested like you can’t wait to hear what he finally says. It means the world to us when people give us their undivided attention. Because we are not used it in this fast paced world! Best of luck to you both!