Everybody is different about how they feel with their stutter. I feel like mine is similar to your new friend's. I'm fine with 1 or 2 remarks/laughs when I first meet someone, but after that there's a level of patient respect that I feel like I deserve. I can tell the difference between caring help and someone finishing sentences to just be a dick about it. Sorry if this isn't too helpful, but it changes from person to person. TL;DR: My advice is just be patient and give him the time to talk. Eventually you can figure out what his preferences are towards the subject.