It sucks to be Futoshi knowing how hard he got NTR'd by Kokoro, but in a strange twist of fate, I feel worse for Mitsuru.
The likelihood that he was in love with Hiro made him much more sympathetic/tolerable, especially when he's attracted both Futoshi's ire and Kokoru's thirst when he just wanted to be sad in peace.
If they aren't just going to make their sexualities a cop-out, it'll be interesting to see how Mitsuru and Ikuno work with those around them knowing that they are a pair that is only compatible because they are both mutually on the DL.