How to get your ex girlfriend back while she's on the rebound?

my ex-girlfriend and i was engaged till she left me for her ex-boyfriend. Now, they are unhappily engaged and probably going to split up. I really love her and want her back. If they do split what would be the best solution to go about getting her back. (she's been cheating on him with me)How to get your ex girlfriend back while she's on the rebound?
your going to spend your life hoping she breaks up with this guy? come on, do you have any idea how many women are out there. good women. look what she did to you. if you think for one second she wont do it again your nuts. find a good girl. this one is obviously confused and unloyal.How to get your ex girlfriend back while she's on the rebound?
well first of all thats Wrong of her to leave u for an Ex in the first place, but i know everyone makes mistakes! Remember This someone can make an mistake once u can 4give them %26amp; if they do it again an 2nd time! Theres no stoppin them theyll just keep on. But i really understand tho! ive been through the same thing. tell her its U or Him!!! put ur foot Down!! and let her know if she gets back with she better not leave u again