Dramione is definitely far from my OTP, but my spare time (I think I already told you) I am a validator for Hawthorn & Vine so I spend part of every other week in that world.
There are some interesting eighth-year themes that are common to that pairing. One I keep running into is Head Boy Must Room With Head Girl. Usually, the excuse is that Hermione and Draco have returned to finish their education, but oh no! What to do? All the beds are full! Before you know it, they are thrown together in their own cozy suite, where sparks fly and hilarity ensues.
To my way of thinking, this idea is almost as implausible as the Marriage Law.
There's a whole gigantic castle full of rooms. Why would Hogwarts administration ever be forced to make the Head Boy and Head Girl share quarters? Do you mean to tell me there's never been an instance where they were pressed for space and had to create makeshift accommodations? Not in the school's entire 1,100-year history?
And then there's the whole proximity issue. You stick two horny teenagers in close quarters, where they receive a 24-hour dose of the other's scent, naturally they're going to start wanting to shag like rabbits. It's a simple matter of phermones. You can't tell me a Hogwarts headmaster is not an expert on the matter. They've carefully segregated the male and female population for seven years - why stop now?
No, the only plausable explanation why the Head Boy and Head Girl would be allowed to share quarters at Hogwarts is because Someone is hoping that those two crazy kids will get to spawnin'.
Think about it.The best and brightest witch and wizard of their year, thrown together right in the start of their prime baby-making years? This is not the result of faulty space planning at Hogwarts - it's an insidious eugenics program! The magical population must be regenerated!
Don't you think that would make a fantastic story? Hermione and Draco are inexplicably forced to room together ... Headmistress McGonagall is suspiciously sanguine about it ... gradually the two of them uncover a meddlesome plot at Hogwarts to bolster the species and produce genetically-superior magical babies through a careful breeding program. How far up does the conspiracy go? Can Hermione and Draco uncover the truth before they run out of condoms? And why does Narcissa look so smug? Tune in next time!