I like to think this image was taken just a few seconds before she slid back a couple more inches and smothered him completely. He looks to be pretty firmly fixed in place. Arms outstretched and held with straps. What looks to be some sort of plastic wrap around his legs. And I think there’s a ball gag in his mouth. She’s been slowly teasing him for the last few minutes, building the anticipation, rubbing back and forth, moving just a little further back each time. Her scent fill his nostrils, and there’s absolutely nothing he can do to stop that final motion that will trap him beneath her beautiful bottom.
I found this image on ‘The diary of a male sub‘ tumblr site. The owner does a nice job of modifying images to keep a consistent theme to his blog, but as usual all attribution tends to get lost in the process, so I’ve no idea of the original source.
Updated: Thanks to FrenchGuy in the comments below for letting me know this is Bobbi Starr in a Divine Bitches shoot. With the help of their useful (if clunky) search function I managed to track it down to this June 2010 live shoot.