All this **** about going out on a night works for a small percentage of guys that are really infatuated/deep in love, because you'll find that all they will do will compare other girls to her, how they miss her, how they would be doing something right now if they were with her.
By all means try this, however I suggest speaking with her one more time, but this time, try and step back from the situation a little bit and see if she's making excuses, or has some ulterior motives as to why she's leaving you - then, you will have a grounded answer (even if it's seeing someone else), and will be able to progress moving on much more productively.