Now for the man2man version: tops like it cause they can feel the fatty part of the ass as they pound with balls slapping, it's also a very dominant position and for those not so very homo don't have to encounter the male anatomy of the bottom(dick/balls) during penetration. Doggy is often preferred by the bottom if the top is very hung because it's an easier position as the dick doesn't go as deep as in missionary and other positions. Kissing, fondling of nipples, neck kissing/biting, ear licking, dick/balls stroking of the bottom and fingering, ass slapping, etc. also are enjoyed by all in this position.