I'll recap:
Me: Do you think someone not producing, distributing, purchasing or, in any way, creating more demand for child porn is doing harm to anyone?
You: No, not in that very narrow instance. Do you?
Me: So, since it meets your Big 3, "Makes people happy", "More personal freedom" and "Doesn't affect anyone else", you'd be fine with legalizing the possession of child porn, in this very narrow case, of course?
You: No, the production of child porn is harmful. Any association with child porn should remain illegal.