There is no rhyme or reason as to what turns people on sexually. I have known guys who had zero interest in breasts- and yet were drawn like a magnet to shapely legs or a large behind.
And an amazing number of people are sexually aroused by feet as seen by the dozens of foot and shoe fetish clubs at Yahoo.
It certainly is one of the great mysteries in life why different people are turned on (or off) by different parts of the body.