Accepting the Truth
If the worst happens, and she laughs in your face, or worse yet, tells you she doesn't love you anymore, you have to accept her words as the absolute truth. Don't try to convince her to love you with rational reasons and an Excel spreadsheet detailing why you're perfect for her. Don't peddle your love to her like it's an about-to-expire carton of milk. Save yourself the embarrassment: Walk away with your dignity intact. Not every love is meant to last forever.
Don't be one of those terrible ex-boyfriends that refuses to see the situation for what it is. If you've done everything you could, and made your feelings clear, it's time to let go. On the bright side, remember that rebound sex we argued against earlier? Now you can disregard that advice and sow your wild oats until the chasm in your heart has shrunk to a tiny wormhole.
Things may have ended, but on the bright side, it's summer! You can start again here.