Separation/divorce, child custody arrangements and payments are very complex and individual to each family. It is admirable that you have made an effort to be courteous, and create an amicable relationship with the mother of his children. It sounds as though he was trying to financially support his children, as best he could. You should not involve yourself at any stage with having any opinion, or influence over monetary decisions involving his children. I assume, since he is paying the mother of his children larger sums of child support (than determined by the Child support calculator) that he can afford it on his current income. The calculator is a gross underestimate of what it takes to raise a child, in a joint parenting arrangement (or not). I also assume, that you are aware of the mother of his children's income as well. You do not know what expenditures she spends on these children/that are required for his children in each household. It will also vary, as they grow into adolescents. The manner in which these children were to be raised was determined long before you entered into a relationship with their father. You do not know what conversations he has had/continues to have, with the mother of his children, when you are not present. There is a multitude of financial facets that they are both responsible for delivering (in addition to basic household costs). Schooling, camps, extra curricula activities, health care, dental/Orthodontics, Optometry, tutoring, birthdays, Christmas, recreational activities and equipment, driving lessons, private health insurance, musical instruments/lessons, School holiday programs or holidays, IT equipment, family pets, counselling services or psychological support for the children, tertiary education in the future. Etc, etc.. It is endless, and specific to the age and developmental needs of each child. The costs will increase as they continue to grow. He has the option of seeking legal advice or mediation (as she may have already done), if he thinks this is necessary. Either way, it has nothing to do with you. ... View more