In the latest everythingbutt.com release, there is some nice, deep, explicit sniffing. Ashley Fires tells Aiden Aspen to do it, and she does. I like it much better when a girl does it on her own, but this is still good stuff. Links can be found here (not verified... I got it by torrent):

http://bitchshare.com/2012/01/butt-s...den-aspen.html