"The aggravating features are two-fold. Firstly, because of their ages they were not only vulnerable but they were quite defenceless, and secondly, you abused the most important position of trust, that of a father for his children. I look for mitigating features. I bear in mind you have pleaded guilty and I accept that you have a mental history which may provide some explanation for your actions although I believe that your motivation was simply malice, malice towards these children's mother."