thinking about bisexual shindou(he doesn't know that yet) dating tatami before the license exam and not really being interested in guys but then. katsuki.
and shindou just ends up having a bi panic because yes, he really really really likes tatami(he really does, he loves her) but also katsuki is just so hot??? and handsome??? and he just wants to kiss him???
tatami finds it extremely funny(and endearing) watching her boyfriend blush like crazy whenever someone from their group points out his crush and stutter in denial, but she also tells him it's okay. and if katsuki also feels the same way towards yo, they could try a polyamorous relationship. yo is genuinely happy that his girlfriend accepts him the way he is.
somehow the group manages to spot katsuki in the mall and the three of them leave yo alone(who's panicking and is an absolute mess, sending half-threatening-half-pleading gazes their way, tatami laughs her ass off), and he manages to talk with katsuki(and even gets his number!! "tatami tatami tatami-" "what?" "i got his fucking number tatami he gave me his number oh my god-")
turns out katsuki is okay with a polyamorous relationship. yo and tatami get a cuddling buddy(who also serves as a heater). tatami and katsuki find ways to torture yo(who had an unlucky experience to have a crush on two handsome people who KNOW he has a crush on them). and katsuki receives 2x more affection.