When people commonly speak of fetishes, they're referring to what's known in psychiatry as "fetishism." One example is the underwear fetish. At what point is this considered an illness?!
Good. I initiate you into 
the art of fetishism.
Perfekt. Ich werde dich in die
Kunst des Fetischismus einführen.
Bien, te he iniciado en 
el arte del fetichismo.
Bien, te he iniciado en 
el arte del fetichismo.
Bene. Ti inizierò all'arte del feticismo.
Certo. Vou te iniciar na arte do fetichismo.