When I went on the first date with my girlfriend of now 5 years, she kept asking me if I was nervous and I just said chuckled, said no and asked why she thought that and she "oh no reason." About a year later she told me that she had at first thought my stutter was just because I was nervous around her and she had felt awful about that for so long after she had realized I actually did have a stutter, and she had been too embarrassed to tell me before that point. I had completely forgotten about it before she told me but we had a good laugh over it.