Fantasy of mine too , but I think can only work if staged.  
It could take a whole evening !
Xoxox
Vanessa

if you met the provider at a local Whole Foods store.

I have been able to do this before! In the end the guy chickened out however, It's possible with a girl who's attractive and good at talking to people. You also have to be at the right location!

The best experience was professionally...  

I met the gentleman at the bar and we enjoyed a couple of cocktails; we are both fairly sexually adventurous folks, so we both started scouting the bar. The first woman, I chatted up was flirtatious, but ended up being a bit more conservative than we had hoped. The second woman, turned out to be a super hot ex porn star that was staying at the hotel. We had a few more cocktails and made our way up the his room. From there, that wild threesome turned into a bit of a orgy as I invited my friend / male duo partner & he brought along his fuck buddy that was with him at the time. Eight hours of crazy, hot, sexy, fun and lots of laughter ensued - and it was magical!  

I highly recommend that if you want it to happen for you, just ask. You'd be surprised what exciting things can come your way from simply communicating your desires & acting on them... with consent of course.  

Have fun!