crack pairing
A romantic pairing (whether it be from a video game, movie, book, etc) that is completely implausible and/or bizarre, but people support it anyway, for laughs or otherwise.
Barret x Red XIII is a crack pairing.
crack pairing
Romantic pairings (usually from movies, TV, video games etc.) that are dreamed up by uber-fans who were obviously high on crack.
Yuffie and Rufus from FFVII is defiantly a crack pairing.