There are no "fool-proof" ways. You just try and if she does not want to then you must move on and let her be.
Make her jealous, Or talk to her.
No, you should not email your ex girlfriend to try and get her back because she has another boyfriend. You had your chance to make the relationship work out with her and since you didn't then it time for both of you to go your separate ways.
If they have a girlfriend they do not want you back.
yes.
I am a girl and i would NEVER get back with my ex.
let him go
Leave her alone.
no
If you are indeed keen on getting your ex girlfriend back, even if her ex boyfriend want her back, what you can do to make sure that he will choose you is make her see your best foot forward. Show her how better you are over her ex, how happy you can become if she decided to come back to you and how things will be better now.
no she doesent
because this preson still has feelings for his ex-girlfriend
If you really want your ex girlfriend back, I would just talk her about your true feelings. It really depends on how long you have been apart.