pairing meme

Stealing this meme from caiusmajor and spacehussy.

Give me a pairing 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