all the suspense really fell out of this one like 10 chapters ago, huh?
Yes, looks like the author is milking us
Rio is like a rotten onion, she looks ok at surface, but each time when remove a layer we find we find a new level o rotteness.
At surface she act like a good friend with strange quotes, but when we remove this layer we find the cheater who sleep with friend's husband and likes to brags about It: "Kyouka, do you fall for him? So take a looks at this photo of me and him going out". Online she act like she is knows the true about monogamic relationship and how se is happy having a husband and a lovers, but this is just a lie she tell to herself, the true Rio is coward and spitifull woman.
And the earing storis sees true, that son of a bitch give Mahoro the earing that Rio don't want more