This was a very amusing conversation I had with a friend's almost three-year-old daughter a few weeks ago:
The little girl mumbled something at me and I couldn't understand what she was saying.
Little Girl: Did you do a pop?
Me (trying not to laugh): No.
Little Girl: But you say pardon after you do a pop.
Me: Oh rightio. But you also say it when you can't hear what someone is saying.
Little Girl does a loud burp and then looks at me.
Little Girl: That was a burp. It's like a pop, but it was in my mouth.
I was really fighting to hold back the laughter by then. She is hilarious!