Cheating should never be justified, ever. If your marriage does not work, either ask your partner why it is not working and try to change for better, or seek help from marriage counselor. If things doesn't work at all, then divorce and find a new partner later. Think rationally. With cheating, you're not only hurting your partner, but also your cheater's partner (and their children if they have them). And do not be surprised that after you got together with your affair partner, that they will cheat on you with another person. There is a reason why the saying "once a cheater will always be a cheater" exist you know.
As usual, people are still rooting for those two. Still think there's nothing wrong with those two right? Still think that their partners are in the wrong right? Still think that those two should just have an affair, no matter how wrong that is right? Sigh.
And even though I don't really like people like Hana, I do agree with her on the friendship between women thing.