Actually it all comes down to my level of stress while speaking. If I speak german or french with a native, of course I'm going to be nervous, so I'm probably going to stutter more. But if I speak italian, spanish or english, then I'm more relaxed, because I'm aware of my language skills and I can speak without having to worry about making serious mistakes, so I'm going to stutter much less or not at all as a result. My stutter adds that additional difficulty lol. I don't mind though.