"I'm afraid I do not know what you're talking about," He says defensively at your question, crossing his arms over his chest. "That is an utterly ridiculous assumption. I cannot believe you would ever think something so sappy would ever come from me."
A heavy sigh comes out of him, and he furrows his eyebrows. "I do not have a favorite sibling, and it certainly isn't you. What a baseless accusation."
Except it isn't baseless. At all. He's literally sitting between your legs in his room, letting you touch his pets (he never lets anyone do that ever, his pets are much too precious), letting you touch him, more importantly—albeit, tiny touches, but that's incredible progress—and you're reading to him.
He has to admit, you're exactly what he needs from a sibling. You call him out on things, but not like Drake does. You treat him like what he is, like a child, but you don't baby him, like Grayson. You take him seriously, but not too seriously, like Bruce. You're pretty quiet, too, which he definitely appreciates.
That does not matter. He doesn't have a favorite. He doesn't like any of you.