if i HAD to choose, i'd go with ass.
it's ironic, because i'm a total tit man, but there's just something about a flat ass that is NOT appealing. i enjoy watching hips sway, and a nice round butt is just damn hot.
i can live without big tits, although i love them (especially tittyfucking).
it's fortunate that my wife has nice big tits and a round bubble butt. her ass just sort of popped up out of nowhere, and i can't keep my hands off of it.
it's a sweltering day here in sunny Los Angeles, and we just came back home and hopped into a cold shower, but even the cold water couldn't keep me from getting hard just LOOKING at her bum. but i digress.
i once dated a girl who didn't have boobs, but had probably the most amazing ass i had ever seen. she was Egyptian, and that butt was just off the charts. i can't believe i never fawned over it while i could.