Pearl, Gem and Lizzie, who all have a crush on Scott and want to do to turn him straight by any means necessary, seeing Scott in an almost romantic (queerplatonic) relationship with Cleo, an almost woman, and deciding this is the perfect pressure point to push to show Scott his true sexuality.
He already likes Cleo enough to be almost-romantic with them, he already likes Cleo in general, so why not prove to him how much he really likes Cleo?
Pearl, Gem and Lizzie kidnapping Cleo and Scott. Feminizing Cleo, stripping her of her androgyny, doing her makeup and stuffing her breasts and chastising her about claiming to be non-binary because it's obvious that was just a silly little phase to try to seem less 'woman' to seduce Scott, wasn't it? Now that they're all going to show him what he's really attracted to is girls, there's no need to 'pretend' to be non-binary anymore, it's time for Cleo to embrace her womanhood to prove to Scott what he really liked about her.
Pearl + Gem + Lizzie forcibly detransing Cleo, and then forcing her and Scott to fuck, making Scott suck Cleo's breasts and threatening him to compliment her pussy and misgender her and deadname her or they're both dead, and isn't it time for him to admit this whole 'queerplatonic' thing was just his excuse to be in a romantic relationship with a woman without admitting it was romantic? It's time for him to fess up! He likes Cleo, a woman, and so therefore he likes women, and he always has :]