It is a fascination that has eluded me for many years.
I've been told that breasts are what makes a woman feel sexy. So I suppose the sight of big boobs makes a man think of the woman as a potential sexual partner. There's probably some hormone levels being raised there too.
On the other hand I've been also told that it's something in our ancient ancestry that makes breasts seem similar to butt cheeks, thus calling to our primitive instincts to mate. This one I find a bit of a stretch.
Or maybe it's because media portray big breasted women as beautiful thus if you're going out with one other males see it as you being a lucky bastard. Envy ensues, it's a nice feeling to be the object of envy too...
I'm still looking for a good answer to this question -_-'
Ask me anything