Outside of scene people, my best friend (since 9th grade) and his wife know and I have another close friend who also knows. It's gone exceedingly well. All that said, I am very very guarded and reserved about who I would share that with - was still nervous telling them - esp worried vanillaish best friend would not take it well - but it worked out very well. His wife expressed a desire to explore kink, power exchange, petplay etc - my friend struggled a lot with this and was having a hard time coming to grips that his wife wanted that - this led to me discussing my own experiences and proclivities and how I had always had them since I was very young. It took a lot of courage, but he tried for her, and he has taken to it and their marriage is so much stronger now. (not that this is relevent to this discussion)
Anyways, we shared a hotel on vacation last year, we had one of the Disney Vacation Club Villas for a week - it was just the three of us on the trip, except for the last day when two of their kids (19 and 16 year old) drove down to join us. So for all the trip except that last day got to wear. My friend's wife was collared in the room - and that was the first time she had ever been collard in-front of anyone. We had such a good time last year we are doing it again this September.
Being able to be your self around people who are not play partners or scene people is very validating and affirming - as long as you carefully consider the impact on your relationship and WHY you want them to know I think it can awesome to share -but it is also not something you can take back if you choose poorly.