Anna, my first wife was bisexual. Or not. She hadn’t had any good relationships with men before she met me (and our relationship was platonic for a long time; then mostly-platonic, then kinda-platonic, then…) but she thought that was because she hadn’t met any “good guys” yet. Plus I think she just wanted to be “normal,” in a regular marriage with kids and cats and a mortgage. I can’t help but believe if we’d had more sex before we got married she’d have realized sooner that sex with a guy just didn’t satisfy her.
I understand the “bisexuals are just people who won’t admit they’re gay” prejudice, since it was shared by some of my lesbian friends. Much to the displeasure of the token bi in our group (I was the token straight guy) who (based on her history, attitudes, and general behavior) really truly was (and as far as I know, still is) interested in both sexes as people and not just differently-configured genitalia. [I don’t have enough field experience to register a learned opinion, but I think most of the pies in your diagram would consider themselves straight or gay if they’re mostly one color, “except for that one time…”]
I consider myself totally straight, but I am most definitely 100% monogamous, so at this point who cares? (Okay, yes, my wife cares a LOT, but otherwise, not so much.) At a certain point in life, some issues that were of enormous import just don’t get us excited anymore.
Anyway, I enjoyed your article and appreciate that you shared it!