Don't know if this is exactly what you're looking for...it's not really BDSM, but Mulder is certainly in control, and it's gorgeously written. The name Fox is used, but more for comic effect at times (yeah, she's funny, too). Definitely worth a look. Here's the link:
http://www.squidge.org/ratb/fic/ladyluck_theanimaliwanted1.htm
Also, if you can stand a little Skinner in the mix, Ratadder has one called "Those Hot Winter Nights." Delectable!