Can't promise when I'll answer, but can't resist. ^_^

Stolen from naboru among others.

Give me a pairing, threesome or moresome, and I'll tell you my headcanon for...

1. What they most commonly do during sex (if applicable)
2. Who has the prettier paintjob
3. What they argue about most often
4. Who'd cope best if the other one died
5. The happiest plausible happily-ever-after I can think of for them
6. The most tragic possible ending for them

Might even fic for a few of those, if the bug bites. ^_^