Sienna Miller says she got makeup put on her butt to cover up stretch marks while doing her nude scenes in Factory Girl. She tells Closer magazine:
“They spray makeup all over your body so you don’t see the stretch marks that we girls all have. One day I’ll wake up and my bum will be on the floor.”
To be fair I put makeup on my genitals. Not to cover anything up, just to make my penis appear smaller than it really is. I speak from experience when I say my penis in its natural state would knock women out from awe.