I lost my cheese

Ian (3 in December) has recently potty trained.  He likes to sit indefinitely on his toddler potty, sometimes taking his snack with him (eww), while watching a show.  When he sits so long that my bottom starts to hurt just seeing him, I try to pry him off, but his usual response is, "Wait, I'm pooping.", to which I suspiciously inquire, "Is that the truth?"  "No."  "Thank you for your honesty.  Now, if you want to finish your show, feel free to pull up your pants and sit somewhere more comfortable."  Here is our most recent potty-time conversation:

Ian:  Mom!  I lost my cheese!
Mom:  Where did it go?
Ian:  I dropped it in the potty.  Can you get it?
Mom: No! No no no! [I dash over to inspect/avert any HAZMAT crises]
Ian: Can you get my cheese?
Mom:  That's not cheese.  That's....poop.  Ian, that's your poop.
Ian:  That's not poop.  It's my cheese.
Mom: [Dashing off to flush the goods]
Ian:  Wait, Mommmm!  Bring back my cheese!