In my experience, if she turns you down, but you both handle it maturely, things are a bit weird for a while, but you will still be friends.
Then after a while you both begin to be more comforatable around eachother again (sometimes active steps are needed, where you have to pluck up the courage to prove your not embaresed anymore) and you are much closer friends than you where before, and thats almost as good.
But at least you wont be wondering 'what if'.

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