Nietzsche was a wanker: Wagner

Sometimes you come across an odd piece of information .. as in the German Genius by Peter Watson. Wagner and Nietzsche were good friends until late 1870's. Wagner died 1883 and only after that Nietzsche wrote about his music being a "disease".
They certainly had artistic disagreements, but the actual reason of their breakup may have been that Wagner quite literally called Nietzsche a wanker. Here's the context:
Nietzsche was in bad health, losing his sight, and visited a doctor in Switzerland 1877. Nietzsche wrote to Wagner about this consultation and in his letter added an essay about Wagner's music written by his doctor. Wagner later thanked the doctor for the essay and mentioned (as was believed at the time) that blindness can be a result of masturbation. The doctor confirmed that this indeed was Nietzsche's habit.
"The details of this exchange circulated during the Bayreuth festival if 1882, coming to Nietzsche's own notice later that same year" writes Watson. Nietzsche was not pleased.