What are some good questions to ask at the beginning of changing a monogamous relationship into a polyamorous one? My husband and I recently decided to make this change, we've talked about it for a while and this is something we've agreed on. However, I want to make sure we cover all our bases on everything that might need to be discussed.
First off - and I know this isn't the answer you were looking for - let go of the idea that you can actually get all your bases covered. There is no foolproof way to ensure that no one gets hurt or that nothing unexpected comes up. You can't prepare for everything. This isn't just true of opening up a relationship - it's true of everything. I just listened to a podcast about the killing of Osama bin Laden - they had everything lined up perfectly, all their "bases covered," and then a helicopter crashed. Some things you just can't protect yourself from, even if you prepare thoroughly.
But, you are correct that there are things you can do to lay a strong foundation for your relationship. My recommendations - and this is not an exhaustive list - are to at least discuss:
What are your best-case-scenarios? Indulge in daydreams and outline exactly what you'd get in a perfect world. Do both of your fantasy futures line up perfectly? (If so, one of you probably isn't being totally honest.) Where there are gaps, dig in and discuss. Consider reading accounts of polyamory (check my resources page) and discussing what you do and don't like, what you do and don't want, etc.
What are your worst-case-scenarios? What are you most afraid of? What would be a complete dealbreaker for you? Relatedly, what are some "rough spots" you anticipate not enjoying, but wouldn't consider absolute dealbreakers? Again, wherever you two aren't totally aligned, dig in and discuss.
How do you two plan to present this new relationship to friends, family, and potential new partners? Do either of you have personal or professional concerns? How will you present a united front? Does someone want to be more open or more private about this than the other person? How will you navigate that?
How are you defining everything? For words you two have been using (monogamous, polyamorous, relationship, partner, sex, etc.) make sure you two have the same definition. It's easy to assume you both mean the same thing when you say "relationship," but that's actually a pretty nebulous word!
How will you manage "couples privilege"? This probably will come up in your best-case/worst-case discussion and your definitions talk, but should be placed on the table explicitly. Are you going into this as a solid couple unit who will make decisions together about new partners, whether to re-close the relationship, etc. or are you two polyamorous individuals free to explore dating externally? If being polyamorous together doesn't work out, is your intention to re-close the relationship or break up?
Those are some conversation starters - you will probably find many more things to talk about as you begin this journey. Note that I didn't talk about "rules" like "veto power," or "sexual limits," etc. In my experience, setting up rules like "no sex on the first date" or "no saying 'I love you' to other partners" have the opposite of their intended effect. Rather than add more coverage for your bases, they just create new bases that can then become points of conflict or require more coverage. Best of luck!