There's a pair of boots, I don't think a woman would walk around wearing clunky boots unless it happens that the style is chic as of the pictures date in time. Ergo, I postulate that the one sitting on the toilet is male. Further more I believe that the male was asked to remove his heavy footwear, as to avoid stepping and hurting the feet of the woman at the front of the spectacle.
Thus I believe the figure in the middle is most likely male while the one at the front is female, while the one on the end of the line is either female or male, further examination would leave me to believe that they are female, judging by the colorful socks, on display, which would seem out of place on a male's more utiliarian mind, who would purchase a cheap brand of simple white crew socks and not a more expensive and comfortable brand of socks with more design elements.
Actually, these all look female. TF?