This has happened on more than one occasion; you go out with your friends and you spot a younge couple on a date. Be it day or night, it makes no difference, it is uncomfortable for atleast one of the parties there.
Personally, I met a few people I knew on my very first date-which was in broad daylight, and although far from any Jewish area, it was a gorgeous day to be outside, hence the Jews traveled out of there way and we bumped into each other. Since then, if I happen to ever meet people when I'm out on a date, and we make eye contact, I smile (from far) or just say 'hi, how are you' and move on with my date.
There are some people who are more 'shy' and prefer to remain 'inconspicuous', even though they know they have been 'spotted' out. Hopefully, the person who 'spot's them gets the hint by noticing the obvious avoidance of eye contact and walks out. Then again, there are those who aren't that perceptive and who will walk on over, introduce themselves to your 'beau' and have a 5 minute chat. Lucky for me, I've had one of those stop by my table at a restaurant once and talk to my date for 10 minutes. He also asked my date what his name was, how old he was, what he does, etc. Weird-but what can you do? smile and move along.
Point being, you gotta know when to meet and greet, or when to get the hint and just beat. For example, I've seen a few people out on dates and knowing the people on the date-if I knew they were the type to be embarassed to be seen, I looked the other way, walked all the way to the other side of the room and made myself distracted to save the date of embarassment or knowing she was seen. If I see someone that I know would be insulted if I wouldn't smile-or someone I know who gives me the look-that puppydog-eyed- look that says "PLEASE SAVE ME NOW", then I do what anyone in that situation would want-I walk over and save her, or make eye contact to meet @ the bathroom in 5.
I guess that makes me both-a greeter and beater-depending on the person I spot, or the person that spots me, which in my case would work as follows: friend or friendly=greet, yenta or nuisance=BEAT!