Being open and honest is the best thing you can do for yourself and your relationship.. In my relationship my significant other knew I stuttered but I was never truly honest about how much it affected me and it did put strain on our relationship it was only until recently that I finally opened up to her fully and expressed the hardships of how stuttering affects most of us mentally / emotionally that she understood why I was how I was in our relationship.. If it makes it easier show him this post and your previous one and even let him read some other posts on here that you can relate to