I stutter more around family than I do friends or strangers. Anyone relate to that?

I stutter more around family than I do friends or strangers. Anyone relate to that? I tend to stutter around my brother and mother the most or people I'm extremely close with. At work or back in school most people I see everyday didn't even know I had a stutter I don't know the reasons behind that if you can explain or share your similar experience that would be appreciated.