My boyfriend stutters and he didn’t mention it before our first date either. He said he appreciated that I was patient and still remained talkative and interested throughout the date. I definitely second the keeping eye contact no matter how long it takes and not bringing it up unless he does. He said other girls would kinda get quiet to “save him the struggle” and he didn’t like that so just keep asking get to know you questions like one would on a first date. I don’t think two people are exactly the same but if he’s insecure about it or seems nervous reassurance afterwards could help- just letting him know you had a good time. Good luck! He sounds like an awesome guy :)