Freddy Fazbear: I personally think he's heterosexual and may or may not be asexual for obvious reasons ;). But I'm also open to him possibly being heteroflexible just for funsies.
Bonnie: He's gay,this boy is gay. He doesn't strike me as the type to be interested in girls. And I can't see him being with any of the female characters in the franchise for some odd reason.
Toy Bonnie: Pansexual demiboy! I know most people headcanon him to be gay because of how he's designed canonically in the game. Seeing as how he's stereotypically feminine. But personally I see him as pan and married to Bonnie in my au.
Chica: Now she was a hard one. Cause on the one hand,I see her as bi with a male preference. On the other hand I kind of think she's straight. So I've decided to go with both.
Foxy: Also Bisexual but with a fem preference. Just because.
Mangle: Omnisexual and very much genderfluid. The end.
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Bonus! For my fanchildren and fnaf OCS(Of whom I will draw later btw)
Darling: Demiaroace! She doesn't fall in love with anyone unless she gets to know them first :).
Puppiet: Aromantic lesbian. Though she mostly isn't interested in romance. I'd like to think that whenever she does feel attracted to someone they're always a woman or at least fem presenting.
Keicha: Pansexual,she doesn't care all too much Abt the gender of her partner.
Christa: Aroace. This girl couldn't give two flying fucks about dating. But supports her friends and family and their romantics relationships.
Toby: Biromantic asexual. But with a heavy male preference.
Moxy: I'd say demiromantic asexual for her. If not then she's lesbian. I lowkey can't decide for her. ;-;
And that's all for today! Please keep in mind that not all of these are canon. Especially my fankids' sexualities. This is purely for fun. At best I'd say that all of these LGBTQ headcanons are only semi-canon in my au.