Dexter and Dee Dee in “Unfinished Business”

THERE! NOW NO ONE'S GETTING IN! [maniacal laugh]

Hmmm... Yep. No one's getting into Dexter's Lab now. [leaves as Dexter's smile of insanity turns into a look of horror]

Uh, oh my dear... In my overwhelming zeal to banish my sister from the lab, I have indeed locked myself out! Too blinded was I not to foresee the most piteous of fates. I have thus performed the ultimate tragic irony! [now standing in front of the 'The End' title card] Surely, I am the fool of fools on a par with no other. I am no better than that stupid coyote or that crazy duck! Look at me, look at me! I am locked in a continuum of cartoon fools! I am doomed to a life of comic mishap adventures and social indignations! And now, here I stand before you, beaten, defeated and alone...