Love triangle problem..

Ok I met this girl about half a year ago and we get along amazing, we talk all the time, etc etc. She was single at the time and I have fallen in love with her and she has fallen in love with me. However her boyfriend/exbf of 3-4 years is still in the picture they keep going out and breaking up and going out. Honestly Its ridiculous how they are. They fight lots and everything. I have talked to her about it a lot and she keeps going back and forth on what to do. Apparantly they dont do anything sexual even kissing because she isnt attracted to him so its more like they are just friends to me but they concider eachother boyfriend girlfriend. I concider her my girlfriend also tho and she is very attracted to me. He doesnt treat her very well and I would treat her properly and she knows that but she wont make the move. It hurts me knowing that I cannot have her I dont know what to do I’ve thought a lot about just letting her go but Im to in love with her to do that so I can’t do that.. We get along perfect, she is my everything, we always can make each other happy, and all that goodstuff. Any advice on making her see that I am the obvious choice? or break them up or something(I know that sounds bad)

Shes 20 btw