Case in point:

American Pie vs The Black Swan (or, if you haven't seen Black Swan yet, Pleasantville)

The act of male masturbation is frequently the butt of immature jokes in the media, but the act of female masturbation is portrayed as beautiful and romantic.

Why the disparity?
...:

How do you figure?

Do you have any examples of that? Anecdotal evidence means nothing to me.
Spanx:

Newports and Super Silver Haze; but that has nothing to do with the subject at hand.

Seriously, rent Pleasantville and American Pie, watch them back to back, go see The Black Swan and try to say with a straight face that the media does not stigmatize male masturbation and romanticize female masturbation.

I dare you.