The older we get the more we notice even if we dont want to. Certainly our sexual vocabulary increases in what we want, how we want it, and what we know we must do to get it. We begin to notice the nuance of a touch, the sensuality of someones smile and how the way someone acts to and with us is the very best foreplay. We need the look and feel of body parts just as much as ever, but beyond the hubris of youth, a certain bloom is off the rose, not that we dont still like looking at the rose, but the pedals and stem attract us just as much.
This is why the disembodied cock isnt as attractive as it might have once been.
Gay men and straight girls might be fascinated by the male member, but as they grow older, it depends more who the dick is attached to then it does the dick itself to inform the attractiveness of that dick. Used to be, one could marvel over a thick bulge and never raise ones eyes to the face of the man who sported that heavy crotch; as one grows older, the crotch-no matter how attractive-does not exist independent from the man. Something shifts in our psyches as we feel a little seasoning and body parts, no matter how thick or long, are simply just body parts.
In most cases, no matter their age, straight women never objectify male parts as much as straight men objectify a womans tits, ass everything, part and parcel from the woman they are attracted to. Gay men to, because they have the same parts as their lover, do not have as much a fascination for objectification. Its not to say any of us, whatever sex or sexual orientation, dont enjoy looking at or touching the bounce, firmness, thickness, roundness or length of a specific naughty pink part from time to time, its just that as time wears on we are less apt to find only the part itself attractive separate from the person whose part it is, doubly so if one is a hetero or a gay man who didnt really objectify all that much to begin with.
Though certainly championed in advertising and in porn, regardless of size, the cock itself means very little to anyone truly unless attached to a man whom one wants to know.