soft touches, tickling or the infliction of pain are all sensual expereiences alike and the brain can circumstancually interpret each of them as pleasure. Similarly ceratin people will experience a high from beeing in a dominant or a submissive position. Its natural, and you don't need Nietzsche to explain such sexual fancies.

However, when it comes to the point that your whole life evolves around your sexual fanatsies (i.e. the stage when partners start to introduce one another other as master and pet and sleep in each others cages) then I'd say that you have reached a stage of perversion and thats just not healthy. Nietsche might not agree, but then maybe there is a reason why he had a mental break down.