Polyamory is just as bad as cheating in its effects on the soul so it’s irrelevant to justify his actions, nevertheless I can tell this is going to suck in the sense bad stuff is going to happen.
Open ending I think, they’re not together but it seems that might happen in the future, naturally in a place we’ll never see it. Kinda disappointed on this ending, which happens rarely.
this is going to be an agonizing wait til the next chapter. taishou was full of painful cliffhangers like this too but i read that after it was finished