"Pascalsuva" is an excellent video which explains how the male sexual response triggers super sensitive spots within our breasts. These are actually responsible for giving our breasts that round sexy look, but the real secret here is that this is only one response that our breasts have to being stimulated. There is another major difference between the British and American busty big asses. Whereas the British ones are dominated by a more upright posture and have a short neckline the American ones are long and slimmer from top to bottom. I guess it just depends on how much of a fatty booty you want..