My DP and his Ex have agreed for us to have DSS 5 nights per week and her two. DP used to have DSS 2 nights per week IF she actually let him so this varied. He has always paid child maintenance, both the agreed rate by CMS and more for anything he needs/asks for. We have done the online calculator to see what she would have to pay him and with this arrangement he would still be paying his ex child maintenance even though we would be having her mainly, how is this right am I missing something?