That's de Sade in a nutshell: telling you what a libertine he thinks he is, while being endlessly repetitive to make sure you remember that rules are being broken. Aims for transgressive, lands on boring. Justine is like that, too; after a while it's less "oh no, poor Justine, set upon by all these creatures of lust" and more "what haven't they done yet? let's tuck that in. Oh we did that? Let's triple it up".