Haven't they been separated for a while before that? I'm sure they have both moved on to a certain extent. Plus, there were rumors that she was cheating on him. If that was the case, then i'd probably wouldn't want anything to do with her either. But if he was the one cheating, then I'm with you, he would be a dbag.
The media liked to think she was cheating on Orlando with Leonardo DiCaprio but people who saw them together in the club said they were just causally chatting to each other, as Leo knows Orlando. I don't think Miranda would have cheated on Orlando with Leo, as Leo seems to go for women around 24-26, blonde and they never have a child.
I don't think Miranda cheated on Orlando at all... Especially cause the rumours are about two pretty famous people, JBieber and LeoD... If she had, we would've seen lots of "evidence", like videos, and people talking, pics... Don't think this could actually go under the radar. But we don't know the resons why they separated, we don't get to live their lives and know exactly what was goin on or how things would go between the two...
And honestly, Miranda was with him for fame? Oh, come on... This is sooo old and boring... She didn't want to go out with him, he asked multiple times... People always say Miranda uses anything to get attention, I'm guessing no one thought it could be wrong, huh? That magazines and paps and celebs websites would use her b/c she has a level of influence and fame? I don't think she would actually call and stuff.