Ethan nodded very seriously.
"That's right, there's only one Ethan in this world, and there will never be a second. Even if there were, Charlotte Green would only want this Ethan, because this Ethan is the only one for Charlotte Green. Do you understand?"
With his lips pursed and twisting a little finger, Ethan thought for a moment, "I understand. Charlotte Green only wants me, Ethan, and that ring also only wants the one Dad gave. If you give another, it becomes the second one, it's like Charlotte Green and Dad having another daughter for me, which would be the second one, not the same."
Uh... How did he manage to relate that?
But, it seems to make some sense.
Charlotte Green looked at her son with incredulity, especially the way he nodded knowingly after saying 'not the same' as if he'd had an epiphany. Aside from being clever beyond his years, what else could she say?