When I met my girlfriend, I was quite afraid of telling her that I stutter. She didn't knew because I actually didn't stutter the first few times I talked to her. Then eventually I just told her and she didn't care, she's been very supportive. To be honest, if someone does have a problem with it, I doubt that person is worth your time, I don't think you want to be around those people. As for a first approach, the only advice I can think of is try to take control of the situation so that you're comfortable with it, maybe simply stepping up to someone just isn't your thing, I know that's never been my thing even if I didn't stutter. I found that if I want to have a conversation with someone that doesn't know I stutter, and I want to feel comfortable about it, first of all I should not worry about what that person might think when they hear me stutter for the first time, that's not going to change anything. I open a conversation with someone just like anyone else would, I know I'm going to stutter and when I do stutter.. what I tend to do is excuse myself and explain that I have this thing, and don't panic. It's like, you know this is going to happen sooner or later, so why not do it right away and take control of it? And you'll also know right away, if that person is worth your time or not.