At this point you are best to let her go as she is being honest with you and needs time. I realize you may not want to do such a thing but she obviously has made her mind up and should take this time for herself. You should also take some time for yourself.
because some guys can be idiots.
because this preson still has feelings for his ex-girlfriend
Your girlfriend may feel jealous when you talk to another girl because she may perceive the interaction as a threat to your relationship. This could stem from insecurities, past experiences, or a fear of losing you to someone else. Communication and reassurance can help address these feelings and strengthen your relationship.
The only thing I can do under stand and move on but, if you're in that situation I can't say, because what ever decision you make you have to live with it.
you wanted him because you couldn't have him, now that you can have him you no longer want him.
This depends on what your feelings really are for her, and if you want to give up.
Be honest with your girlfriend. I have a friend who has a girlfriend but he is in love with his best friend, the longer you leave it then the harder it will get because your feelings for this 'someone else' will not disappear. Depending on how long you have been with your girlfriend it is the time to think whether you will later regret your actions or have any feelings for your current girlfriend. But in this case honesty is the best policy because no girl would or should be lied to if you are in love with someone else then tell your girl!
no because hes dead
Well, not every girl likes to talk about their feelings. Also, some girls find that guys who talk about their feelings are sometimes weak. Some girls don't like when guys talk about how they feel because sometimes they only want it to be about them. But a good girlfriend will listen to you and try to sort things out. So i do suggest talking to your girlfriend and ask her exactly what you're asking me. Another reason could be that she doesn't really care to hear what you have to say. It just depends on the girl.
You should just ignore them and date someone else better then her or him.
Because he probably has feelings for her, that usually happens when 2 people are together. Most guys usually don't cry over they're girlfriend, But guys are different. But they have feelings for that person, and if something happens, he is going to get upset.
You don't... if you love her. Just ask her, if she doesn't want to, find another girlfriend because she is not truly bisexual in that case.