I can't find an explanation for this anywhere - Only stutter around friends/family, please help

I can't find an explanation for this anywhere - Only stutter around friends/family, please help As the title says, I only ever really seem to stutter around friends and family, people I'm close with, never strangers or acquaintances. It doesn't really bother me TOO MUCH as a result but it still is a bit annoying/bothersome. I only recently developed this I think, about a year ago I noticed I'd started doing this. I get a lot of speech blocks in particular, that's the main part - I have to make a genuine effort to try get my words out, i have to try rearrange words in my head or find new words altogether to try say what I want. Sometimes I'll give up on the sentence altogether if it's too hard getting it out. I'm trying to find an explanation as to why this' happening to me to, why it only happens around friends, family yet there seems to be barely anyone with the same experience.