SHAVE IT! I SHAVE MY ENTIRE BODY. ARMS, LEGS, CHEST, ASS, BALLS, AND UNDERAMRS ECT... LADIES SEEM TO LOVE IT FOR THE MOST PART. PLUS IT MAKES MY 7 1/5 LOOK BIGGER. I AM NOT THAT BIG SO I DON'T MIND 7 1/5 LOOKING 8 OR MORE! YA KNOW!
I would ask her first what she prefers....she might find it more disturbing that you shave your ass. It's definitely shit she's going to tell everyone about you after you two break up if she finds it weird or overly vain.
Look on the bright side, at least you're not bald and have hair all growing over your chest, back, arms, and shoulders too....well not yet anyways.