I second the comment about feeling anxious around them and judged by them. I actually stutter around kids because kids make me nervous. I'm not used to being around kids so I stutter worse around them. The same goes for people I feel intimidated by or people who I can tell are judging me. It sucks, but I know I'm stuttering worse because I can feel my confidence dropping the more they stare at me. That's not saying I don't stutter around those I'm comfortable around, but the stutter is certainly worse around those I am not comfortable around.