Everyone listen up.....Still-Asleep has spoken. He is (apparently) all-knowing, and has the corner on all of the hobby world's "absolutes."
The fact is, SA, there are no absolutes in life - not even in the hobby - not even in the Webster's Dictionary you pulled out for your last post.
If I see a provider I personally know in a public setting, all I can say is that I'll treat the situation appropriately. But "appropriately" will likely be different EVERY time. Like Rambo said - saying NOTHING when there's no reason for such behavior is tacky at best - and might come off as "haughty" or even worse. I don't want to portray that image to a provider - especially if I think I might want to see her again. If simple acknowledgement (just like I would acknowledge anyone I know from any aspect of my life) is just as easy, I will do so.
And for what it's worth (anticipating SA's argument of "you never know if....blah blah"), I think that if hobbyists and/or providers aren't ready with a "moment's notice" cover story for such situations with friends/relatives, then they're crazy. We all have multiple "elements" to our lives....case-in-point, I have two areas of my life that have virtually no interaction with each other. My cover is simple.....depending on who I'm with, I'll say, "Oh, I know her from....(the OTHER aspect of my life)." And obviously no names in the conversation - unless you KNOW THAT YOU KNOW her real name.
Other possibilities might include having, "met her at so-and-so's wedding," or "She's friends with so-and-so from the office," or friend of a roommate, etc.
Now - if my acknowledgement of her - or her of me - is inappropriately familiar or attentioin-grabbing - or really if it is ANYTHING more than a friendly "hello," like I would to any personal acquaintance of mine.....like the original post recounts certainly would qualify as......then that kind of behavior better be ONLY because you KNOW you're alone together - and even then, it would usually be tacky (e.g. - the original post story).
But for comparison purposes, I've had 5 such occasions where I found myself connecting "in public" with a provider. Twice, I let her walk by.....one of those times, she never saw me. Once, we made eye contact - I nodded my head very similar to what I might do to a complete stranger if we made eye contact. I might even say "Hi, how you doing?" like I do 25 times a day to complete strangers as I walk past them on the street or in the mall giving them the same look/nod.
In two of my five incidents, it has been one particular lady I've seen several times, and that I know is single - she knows I'm single. And both chance meetings have occurred in places where there was no reason for us not to "chat," so we did. Again - no names dropped during conversation (well - by the second time, I knew her real name - so maybe I said it then....don't remember for sure) - just simple "small-talk" chat like you'd do with your neighbor, or someone who you worked with 5 years ago, or met at a wedding, or whatever.
As to the original post - the guy showed no discretion whatsoever. No situational awareness - and is truly a douche bag. Ladies shouldn't have to put up with that kind of crap - and I'm sorry to hear that you had to deal with this. I do think he's the exception, not the rule.....it's just sad that there are exceptions, period.