[Jamie89]

I wouldn't personally but I agree with the pov that the majority of blame should go to the person who's married. It think regardless of morality, because even if both were equally wrong morally (which personally I don't think they would be, but lets just say for arguments sake they are) there's still the issue of commitment... the single person isn't breaking a commitment they've made, the married person is. And yes they're both willfully hurting someone, but it's the married person who is supposed to care about them and have a responsibility towards them.