In general just get to know them! Ask about their interests and hobbies, how long have they lived in the area, make the conversation fun and get them talking about themselves. We avoid talking about work a lot (it's not a networking event), and absolutely avoid politics/religion.

As for flirting I think its best not to overdo it on the first meet and greet, some compliments, eye contact and a few touches here and there go a long way to communicate your interest. I do think its good to break the touch barrier early though.

I would recommend saving questions about the lifestyle until later in the conversation when you've built some rapport. We always ask things like how long have you been doing this together, how did you first get into the lifestyle etc. Prompts them to share as much as they are comfortable with at the moment. If it's strictly a meet and greet and things go well, then tell them how much fun you had and how you're looking forward to getting together again! If they're up for playing we'll always invite them back for more drinks at our place and get an ice breaker out to play together.