It seems like your friends really care about you. If they do, they won't care that you stutter, and being open with them about it might make you closer in some way, or they won't care about the stutter (as in they won't think any differently of you). Have you and your friends been friends for a long time? Could it be possible they already know you stutter but either don't care about it or they don't want to bring it up in case it's a sensitive topic? Sometime just hanging out with friends without having to talk often feels pretty nice to me. I don't avoid my friends because of my stutter, but all of my close friends know that I stutter anyway.