I'm on my phone and the quote feature is hard to use on it, so I'm skipping it. But I wanted to address the part of your post, Storm, where you were talking about polyfidelity. It sounds like you feel that if anyone is added for more than just friends with benefits that it will have to be in a polyfidelity situation. You talked a lot about "what if we then want to experiment with being bi, it'll be next to impossible." You do realize that it is possible to have a long term, loving, caring secondary relationship without it being polyfi, right? Sure, it's harder, it means more juggling of time and energy than otherwise, but just because someone besides Glitter is in your life long term doesn't mean it has to be a closed relationship.
The poly cluster I'm a member of has very few polyfi relationships (if any) but that doesn't mean any of us are any less committed to our partners than someone who is in a polyfi relationship. My husband and his girlfriend have been together for 3 1/2 years. I've been with my boyfriend for 10 months. My husband's girlfriend is married and has an additional boyfriend who she's been with for over a year. While my boyfriend hasn't dated anyone regularly since we got together, that option is open and he has started dating someone else off and on. Safe sex takes on a special meaning in an open group and time management is sometimes a bitch but it is possible to have long lasting, meaningful relationships that aren't polyfi.