to be honest, grils with big breast are not really into fore-play and get annoyed by how much attention you pay the tits, a chick with big tits mean at least 30minutes of grabbing at, face rubbing, licking titty f***ing etc
she probably wants more attention to her a** or straight poundage...
where as..a small tittied girl with a big a** KNOWS her a** gon get felt and given attention, her nipples will get licked mabye 10coats each...i dunno
aesthetics .... Nice Tittie > Nice a**
practicallity ....Nice a** > Nice titties
but thats just briCKology!