(Based on actual events.)
Younger offspring (age 4.5): (singing softly to self while arranging a line of nine grapes on breakfast plate) Nine planets, fine planets, in our solar system. Nine planets, fine planets, go ahead and list 'em ... *
Elder offspring (age 6.5): You know, in school we learned that they discovered a tenth planet. They used to call it planet X, but now they're callin' it Xena.
Younger offspring: (glowering at sibling and singing louder) NINE planets! FINE planets! In our sol-ar SYStem! NINE planets! FINE planets! Go ahead and LISTthem!
Dr. Free-Ride's better half: (from the next room) Didn't they decide Pluto is too small to be a real planet?
Dr. Free-Ride: Pluto is too a planet! It was a planet when I learned it in school, and it hasn't gotten any smaller since then!
Younger offspring: Pluto is a planet. It's in the song.
Elder offspring: Xena's a planet, too.
Younger offspring: (glower set at full strength) Xena isn't in the song.
Dr. Free-Ride: I think that song was written before they discovered Xena. (To the next room) And Pluto is definitely a planet!
Dr. Free-Ride's better half: Your education is becoming obsolete. Remember the brontosaurus?
Dr. Free-Ride: Shut up! (To younger offspring) Eat your planets.
*The lyrics to the song were very similar -- but not identical -- to those of Nine Fine Planets by John Paul Taylor, Jr. If any of my readers is familiar with this variant -- and can hook me up with the full lyrics -- I'd be much obliged!