Simple answer; you can't.
She can marry whoever she wants. You can talk with her about why you don't want her to, tell her you love her, offer her an ultimatum that you will leave if she does this, but that's pretty much all you can do.
You leave him alone to allow his marriage to work. If he's about to marry someone else, he doesn't love you and you need to move on. Stop thinking about him and find someone new.
If you think you are in love with another person then you should break up with your girlfriend, because that's not fair to her or you.
Girlfriend Someone Please Stop the World - 2004 is rated/received certificates of: Japan:R-15
Get out or stop.
tell him/her you don't want to be their girlfriend/boyfriend! if they don't stop tell them to stop or else you will slap them!
I don't think you can, real love is a commitment and cannot be turned off or on at will. The best you can do (in my opinion) is to let them go and hope that they can be happy now.
You should confront that guy that is flirting with your girlfriend about it. You should say hey i am not cool with you flirting with my girlfriend and i dont like it. Maybe after you say something he will stop but if not then idk haha....
Get a life and find someone else. Geeze,I mean she's already moved on so stop obsessing. It won't help.
You cant stop someone form loving someone else, its impossible. It is also wrong to try.
Tell that jealous person that if they really liked you then they would only want you to be happy, and that your girlfriend makes you happy.
try to think about something else
This is very difficult to do, because your heart doesn't always do what your head tells it to. The only thing that will help is time. If you are sure that you are finished with your old girlfriend, then you just have to wait. Nothing else will do.