You can't. If she is happy, you should move on even if it hurts. The love will stay but the feelings to be with her will pass. If she wants to be with you she will come back, Until then start working on ourslef so you won't have baggage that another girl has to deal with.
Simple Answer: You don't.
You do absolutely nothing about your ex boyfriend considering he has a new girlfriend. If he loved you he would break up with his girlfriend and since he has not then he wants to be with her and you need to accept that. Just because you have broken up with your boyfriend it doesn't mean you can just step back into your ex boyfriend's life.
Let him have a threesome with your sister (only if hot)
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.
im sorry to say but get over hes gone
Thats impossible
You don't.. you wait for him to regret how foolish he was, and come back to you. If not, then it wasn't meant to be.
get over it
if you really love him then let him be happy and live with his family
She probably did it to make the ex- boyfriend jealous.
You should be confronting your ex and telling him you do not like his girlfriend asking your children about your new boyfriend and if it keeps up he will only be able to see his children at your home or without his ex girlfriend.
If she was real, she will not become an ex.