<human>: First of all I want to point out that I don't necessarily think that she is WRONG to be the way she is, nor do I necessarily think I am right to be the way I am.  So here goes.

I have this thing, that is quite possibly just a manifestation of insecurity.  When I think about it logically I know that it shouldn't be a big deal, but for some reason, this hurts my feelings a lot.  When I am with a girl, I don't want anyone else sexually.  It isn't that I don't find other people attractive, just that the idea of having sex with them doesn't sound good at all.  She is all that I need sexually.  More than all that I need, she is all that I want.  She, however, does want other people sexually.  She has cheated on me before, both times when she was extremely drunk (I know it isn't an excuse but it is relevant information), and we are working on building the trust back up.  I know that she loves me and wants to be with me, but she has said before that she feels that she would be better off in an open relationship, but that she would never do that with me because she knows it would hurt my feelings.  I know that I should feel glad that she is giving up something she wants for me, but for some reason, not being the only person she wants, and knowing that, is extremely hurtful.  
I hate how unreasonable I feel when I talk about this. I know it shouldn't matter and that probably everyone wants other people sexually while they are in relationships.  I would really appreciate advice that is conducive to me moving towards a healthy relationship with her.  I don't want to leave her and I won't.

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Can you give me a shortened version of the text?
<bot>: My girlfriend wants other people sexually, and even though I know its ridiculous, it hurts me not to be the only person that she wants.  Advice to help me move towards a healthier relationship would be great.