Some kind of writer of fanfic...

zam is hopelessly in love with graecie

legs is hopelessly in love with graecie, and also a little bit in love with zam

graecie is a little bit in love with everybody she meets, but especially her best friends

For a character to be canonically bi you have to make sure and establish that they're attracted to multiple genders. Not all mediums allow you to get inside every character's head or show what they're thinking. Flirting can be read ambiguously, and god forbid they flirt with a character who's not into them and be read as pushy or predatory. So it can be super handy to just mention an ex or two! But you better not mention too many exes because that would make them a slutty bisexual which is (checks notes) bad, and you definitely better be careful about making them poly, because that might make them, uh... greedy. Oh, and those exes? They better be perfectly amiable breakups with no conflict or drama, because it's bad to represent queer people in toxic or abusive relationships (especially queer women! very bad), and you definitely can't have them have lost a partner if the partner was queer because that's "bury your gays..." You should probably also eliminate all trauma from their backstory, just to be safe. You should probably also make sure they're not involved in crime, deception, or anything of the sort, because that would make them "deviant" and a stereotype.

adventures of legundo and owen (+ louis) in triple ultra super bdouble premium exclusive pro plus super hell

It came to me in a vision and that one tumblr post.

+ Bonus doodle from the Trustbites Magma.