I could see Nadeshiko picking up on that implication and intervening on Jun's behalf, wanting her to get to be happy as well with all three of them. Her saying she doesn't want to share earlier has basically been her most human moment so far, and evolving on that and demonstrating clearly that she values someone isn't her mother or owner would actually be a really good conclusion to her arc as a character.
So are you saying she should offer a poly relationship cuz that’s a horrible idea.
Neither of them are interested in Jun, so it’d freaking suck if they had her join outta pity.
Nadeshiko literally can’t do anything to make Jun happy cuz she doesn’t love her.
Jun’s happy ending will be one where she moves on from Akane or finds another girl.
Akane just needs to turn Jun down, no sugar coating, just be direct, so Jun can mourn over the rejection and move on, knowing that there’s no chance for her feelings to be reciprocated.
Nadeshiko said she didn’t wanna share, her going against that would be wild and would basically make her character development pointless. The whole point of her not wanting to share was because the “selfishness” was a human quality, no human, would agree to share their lover with another person to “show that they care for them”
Poly route isn’t gonna happen and if it does, then i doubt it’ll go well for them and if it does, it’ll feel unnatural since neither nadeshiko nor Akane have shown interest in jun, and Jun hasn’t shown interest in nadeshiko.