I am not surprised to hear that she is an only child - in my experience, they seem to be (on average - yes I am generalizing) more selfish sexually than women w/ siblings.
I have a feeling that this is going to haunt you. I've been there once. Regardless of how little you think this bothers you, feeling unfulfilled often results in small, insignificant issues being blown out of proportion as a manifestation of frustration from another root cause (ie. sexual tension).
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-- apt-get install spare_time --
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