Boyfriends child support paperwork is asking for my (his girlfriends) income

Hello, my boyfriend (29M) and myself (25F) have been together for 6 years. We have two kids together. We are not legally married. 2 weeks ago he recieved Child Support papers from California from his 1st sons mother. We live in another state btw. I'm in no way agasint him paying because every child needs support.. I'm just a little confused. In the section that asks about other members in the household it says to name the person, their age, monthly income, and if they share expenses. We added our two children but I'm not sure if I should add myself because we are not legally married and dont share debt and could break up tomorrow for all they know. I make significantly more than my boyfriend does and I don't understand why my income is needed to calculate his support obligation when I'm not financially responsible his 1st child in anyway. I have my own young children to care for. Are they going to base what he pays each month off mines and his income together resulting in a higher child support payment? Because I don't see a reason why they would ask about someone's income who is not a parent of the child. Please help.