Well those two are friends with benefits, so this case isn’t really poly since none of them are in an actual relationship yet. Imo the MC may end up with the long haired chick
You literally have almost nothing to go on, and both people are interested in her sexually, don't mind sharing, and at least one has expressed romantic interest in the manga (in her thought bubbles), and you're trying to say 1 will be picked over the other? This is like, trying so freaking hard to avoid polyamory. If both of her neighbors are dating her, even if they aren't dating each other, that's polyamory, and that definitely looks like where this is headed.