I'm thinking that I would just blow it off and ask her to go on a date just the two of you. During the date I would make sure I am having a good time and push those feelings of not being good enough in the back ground. Fake it til you make it kind of thing.
Those niggly little self doubt conversations we have with ourselves tend to get in the way of reality. The reality is that she likes you and you like her. What her girlfriend says is nothing to do with you. Being interested is necessary as being interested in her life is impoprtant, but that is a different relationship that you are not welcome in.
This woman is your metamour. Its not manditory you have sex with her, but it is advised that you speak kindy to her/of her and be at least be cordial when you see her. Everything else I advice you let go of as it won't be of benefit in getting more connected to this woman. What she said isn't meant to be personalin terms of your worth.
She might think youi are a great guy, but that is a far cry from having sex with someone. Most of the time two people don't have the same attractions. They could never find a suitable man they both like.
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