Apparently when he says "Ryder's baby," that's exactly what he means

Yesterday Ryder and I were getting ready when Ryder said "Mommy, you have letters on your shirt." So I told him, "Those letters say 'Baby' because of our baby." Ryder laughed a little and said, "It's not your baby. It's just Ryder's baby, not Mommy's baby!" Which of course made me burst out laughing. That apparently wasn't the reaction Ryder wanted because he started to get frustrated and said, "No, it's NOT YOUR BABY, Mommy! It's JUST RYDER'S BABY!" Now, I didn't think he was kidding when he referred to the baby as "Ryder's baby" all the time, but I didn't realize that precluded it from being Mommy and Daddy's baby as well. So I asked, "Well, how about if the baby is Ryder's baby and Mommy's baby and Daddy's baby?" That seemed to be a good idea because his face lit up and he said, "And Grandma and Grandpa's baby!" "Yes, it will be everyone's baby," I told him. Hopefully this is an indication that we won't have too much sibling jealousy to deal with, though hopefully we won't have "nobody else can touch Ryder's baby" syndrome instead!