I'm worried these won't really catch on, but I thought I'd give it a shot.
Bigen (left): An adult referential term for someone who is bigender. The plural form is bigens.
Twain (middle): An age-nonspecific referential term for someone who is bigender. The plural form is twains. Also called duo (duos) or venn (venns.)
Bibby (right): A diminutive referential term for someone who is bigender. The plural form is bibbies.
Bigen was simply a shortening of bigender.
Twain comes from the splitting of something, like breaking something in twain (which is Old English.) Duo references having two genders, while venn comes from Venn diagram (evoking the image of two genders overlapping.)
Bibby comes from the bi- prefix, made to sound childish and cutesy, and it follows the same convention as enby.
That bigen over there has a lot of pride pins on eir backpack. I bet a lot of bigens would be happy to see the bigender one there.
I hear some twains might show up to the party tonight. I have a twain friend who might feel right at home.
Raising a bibby isn't so difficult if you're willing to be patient and listen. Anyone else raising bibbies should take this advice into consideration.
