My 13-year-old brother had us all in stitches this morning. You kind of had to be there to "get it" fully, but I'll see if I can repaint the scene. :)
The four siblings were sitting in Church, and Sarah had David reading aloud
The Universal Prayer of Pope Clement (okay, every version I can find online has a slightly different translation, so that messes up the dialogue a little bit). Anyway, the prayer book we have says, "Lord, make me...diligent in my duties". Now if you know my brother, you know that he can be a little, shall we say, hard to keep focused sometimes. So when we hit that part of the prayer, here's what transpired:
Sarah: Um, sir, repeat that line!
David: "Diligent in my duties"
Sarah: Try it again.
David: "Diligent in my duties"
(Repeat this exchange at least once more)
*Insert sibling chuckles here*
David: Well, I do a pretty good job when I'm motivated.
Me: What about the other 99% of the time?
Sarah: Well, there's this thing call SELF-motivation that you need.
Me: It's interesting, isn't it, all the words that start with "D"? David can either be a distracted, destructive dawdler or a diligent, dutiful...
(Sarah and Claire look at each other, searching for the right "D" word to finish)
David: ...DUDE!