I realized my insecurity had less to do with polyamory and more to do with the diminished quality of time we'd spent together recently--and needing to further clarify how we each wanted the relationship to progress, and at what pace. The jealousy I felt about his in-town lover was really about wishing he and I could spend more time together. This also all came up as several of my closest friends (and recent ex-lovers) in my hometown have been leaving town or coupling off and are less available to me--it's good to notice how important all these relationships are!
Your post was helpful, as were the links you provided. It's really valuable reading other people's stories. I had a good conversation with my lover recently, and I've decided to spend more time focusing on my world here and the people I do get to see everyday--and keeping an eye out for another romance--while holding on to my deep connection with my lover.