i heard in an interview the delancy that he has always had a foot fetish and out of character had a wicked boner during that scene. he was worried it would show up in the episode.
apparently he had very mixed emotions when they had to reshoot it several times. but in the long run he was grateful for the opportunity to add those moments to his internal spank bank. IE he still jerks off to the experience.
personally i think he's a sick man.