He likes doing it to little girls, more particularly....plenty of pictures of the creepy fake toothed clown.
https://www.google.com/search?q=biden+creepy+little+girls&rlz=1C1CHBF_enUS711US711&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjM0LOf9rnXAhVH-2MKHZIsAgoQ_AUICigB&biw=1920&bih=974
He prefers little girls, but little boys get his attention sometimes as well.