Who's in the wrong?

Here is the story. I know this girl and her bf that have been talking since 2003. They have had some serious falling outs in this period. She has insecurities and feel that she can't trust him. But the nucca loves her and would do anything in this world to show it to her. So when they get into arguments she runs to some other nucca for comfort. Only to come running back to to her bf. During a certain period, she with this cut buddy and lying about it. Leaving her man in the dark and not trying to open up to him. So after she drops the cut buddy somehow she finds out that her bf has been talking to other girls. So to avoid an agrument she breaks up with him. But who is in the wrong? The girl for not letting her man be there for her or the nucca trying to find someone else that will act right?What are your opinions?

They're BOTH at fault for no communication...BUT home girl didnt appreciate him which drove him to tryna find a new girl. So I feel she's more at fault.