All of the responses I'm seeing allude to future choices or potential paths in future updates that are WAY far into the story. That doesn't answer my question of why the MC has no ability to express this upfront during the initial relationship/friendship choice, or earlier while talking to each of them after the big reveal. Makes no logical sense to me that this option wasn't included, even if it forks into the same friendship route.
And to the one saying the MC is canonically attracted to both - that's prior to the reveal. Compounded with additional secrets kept beyond the hidden relationship, or being led on and subsequently tased (regardless of whether told to do so - that was shitty), or finding out Josy essentially ghosted her other LI without any sort of closure, etc? There is plenty of grievance fuel sufficient to argue the MC deciding to permanently burning bridges.