Rob should not have to take Kristen back, but if she does these things she might be able to prove that she has learned from her mistakes and is truly sorry for the way she has treated him.
- Give him space so that he doesn't have to deal with being humiliated in public.
- Beg for forgiveness.
- Go to therapy to show that you are trying to get help and work your problems out.
- Leave him alone and try not to speak about him to the media.
- Allow him to feel hate towards you so that he might eventually be able ro remember the good times.
- Become more self-aware and less immature and realize that you are need to be responsible for your actions.
- Be prepared from him not to take you back.
- If he is willing to talk to you, suggest you both go to therapy.
If Rob sees that she's makin an effort to change he might give her another chance, or at least try to stay friends with her.
source: hollywood life