Given my Elder Millenial age group, the mid ninties as the birth of bisexuality rings pretty true on a personal level.
But as someone who thinks that bi is the most natural of sexualites, it's probably the only one that didn't need to be "invented". Homosexuality in the modern sense is quite recent (although same sex attraction itself is timeless) and heterosexuality seems to require an awful lot of policing and enforcement for something that's meant to be "natural"...
Whether the finger guns and leather jackets have always been part of bi identify remains a question for cultural archaeologists.
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