...Incidentally, just to elaborate on what a crack pairing is (the definition I learned):
A romantic pairing between two characters who wouldn't even be considered a potential couple unless the author was insane.
Example: Jimmy Olsen and Martha Kent. To clarify just a bit more;
*Lois/Clark would not be a crack pair, because they're the official canon couple.
*Clark/Mayson would not be a crack pair, because they were basically set up as another possible couple for the show--she was the 'other woman', if you will.
To be a crack pair, there has to be absolutely no in-show basis for the two characters to be a couple.
Is that clear? Of course, no points taken off for already-finished fics that worked it in without the definition.
Although...Y'all may want to keep the definition handy for the future...
