There was a young feller named Xander,
A construction worker, and good with the sander,
He's after the Slayer,
And not just to lay her,
Keep it up, and one day he might land her!
There once was this young girl called Dawn,
Who fic writers kept putting in porn,
The pairings were wacko,
But mainly with Draco,
Ending up naked on Hogwart's front lawn!
Update : And now that I've finished it - Negotiations - 20 minutes with David Nabbit is now up at Twisting the Hellmouth.
I've never used limericks as a way of breaking writer's block before, but hey! If it works...