For me, whenever anyone says anything like this, I feel like it's pandering, even with people I trust completely. I know in my head its not, but it feels like the person is just trying to make me feel better and don't actually mean it. As others have pointed out, it just feels weird or wrong to have someone say its attractive, as its something that I'm sure a large number of us would rather live without, and is a constant source of insecurity. My advice is always to just treat the person the same as you would if they didn't have a stutter, and I'd think most people would agree with that. I do really appreciate you reaching out to ask, I honestly love sharing insight and helping people understand people with stutters better, it makes life easier for us one small bit at a time.