This surprisingly safe for work image is one of the dirtiest, most arousing things I have ever seen.
It's just so suggestive . You can almost see up her skirt. You can see she's got a riding crop, and wants to use it. But you can't see her eyes, and it's impossible to tell from the set of her mouth whether she wants to use it in a nice way or a not-so-nice way.
Wow. Just wow.
The image is from the Very NSFW femdom marriage tumblr at http://fdmarriage.tumblr.com.