I have had some experience (success?) as the "dreaded" solo gentleman exploring the lifestyle. Most of this has been while traveling to the Miami/Ft. Lauderdale area, where swing clubs and couples are more open to and accepting of the solo gentleman.
Based on this experience, I do believe that there are couples and ladies who are looking for folks like me at clubs, but the key is the word "gentleman". I dress appropriately, engage both male and female in the conversation, don't stare or stalk, etc.
On one visit, I was at the bar of a club and was near a few couples when one of the guys says to me "looks like someone knows how to dress". Struck up a conversation to discover that his wife was THE hottest blonde in the place. Which led to introductions, which led to.. well, you can guess the rest.
Any couples reading in the NYC area who are looking for a similar scene, please drop a line ?!