Is my stepmother wart showing?

Confession: Being a stepmother is WAY harder than being a biological mother. I can say this because I am both. My bio son is just a year and a half old and is thoroughly and beautifully exhausting. My stepson, who is equally as thorough and beautiful in his exhaustive nature, is four and a half. I'm not sure if it's being four or if it's the fact that no matter how much I love him, no matter how much I feel like he's my son, SS isn't actually my child. In the end, who does he want for comfort? "Mommy, Daddy, Gigi." I don't even rank above the blanket.