I have a bad habit of looking, at least briefly, at every pair I see. I love to look down the front of my wife's shirt, and she's a 32B. Guys get used to looking at women that way from looking at porn, to be honest. They come to think of women as objects to masturbate inside of. If you don't like guys looking, try covering up a little more - a lot of the women I see look like they dressed that way just to attract the attention.