You know that kink has definitely reached mainstream when Jessica gets a good rough spanking in a movie - and she actually likes it.

http://www.hiphoprx.com/2009/11/09/watch-jessica-alba-get-ass-spanked-in-new-movie-the-killer-inside-me-photos/

Yes, she's a terrible actress, but who the heck cares with such a nice butt ;)