(Technically, I saw this a few days ago on
poisonivory's journal, but I only wound up stealing it today, after I saw it on
thelostmaximoff's journal.)
Give me a pairing and I will tell you:
1. What they most commonly do during sex
2. Who has prettier hair
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.