ISNT THIS THE CUTEST PICTURE EVER???? If you were walking within a mile of Central Park this afternoon, you'd probably have heard a deafening roar of "Awwwww!" That raucous chorus would be the sound of a small army of swooning teens as they watched Robert Pattinson playing big brother to an adorable little girl. So far, the handsome Brit has been playing something of a bad boy in his new m…