A serial public masturbator ejaculated on strangers over many years Muhammad Khan, 40, pleaded guilty to ejaculating on women in public The sex fiend worked as a high-flying finance specialist on $120,000 a year One victim had been watching a mum play a violin when he defiled her in public The predator eventually sexually assaulted a woman at a Melbourne pub Magistrate Tara Hartnett cut him loose and failed to register him as a sex grub