"In the polyamory world, we don't give out toaster ovens for making new converts."
Kink advice columnist Mistress Matisse holds forth on poly etiquette:
In the polyamory world, we don't give out toaster ovens for making new converts that's for the queer people, which is just as well. I can't speak for others, but my record for monogamous-to-polyamorous conversions is pretty low.... I recommend against missionary dating: trying to recruit someone to your sexual group in spite of his or her expressed misgivings.... You're more apt to end up with an electrical fire than a handy household appliance.
Conversationally, deal with poly people's other partners the way you might deal with their children: Acknowledge that these are important people in your desired one's life. Ask a few polite questions about their work or hobbies or whatever. It's showing due respect to their existence. It costs you nothing to create goodwill with the incumbent lovers, and failure to do so could cost you: If Max and Monk told me someone who'd flirted with me had been anything less than courteous to them, well, that would be the end of the flirtation.
And a few remarks for poly people on the prowl. Disclose early and often. Don't hedge about it, or use weasel words like "special friends."...
Read her whole column (July 24, 2008).