That Old Malfoy Charm
It's the prerogative of every sixteen year-old boy to change his mind about whomever he fancies, because that's what teenagers do, act fickle -- at least that's what Hermione told Ron when she threw him over for Ginny. Of course, she'd said sixteen year-old girl instead of boy, and while this really isn't the best example Harry could use to justify his attraction to a certain Slytherin, it's the only rationalisation he's got, plus beggars, choosers and all that.
So when Harry tilts his head to the side during dinner and squints really hard in the general direction of the Slytherin table, he can see how he might possibly -- definitely -- be attracted to a certain arrogant, sniveling Seeker. From this very fuzzy point of view Malfoy really does have a certain charm about him, like a strangely-domesticated ferret, that Harry didn't even realise he wanted to keep as a pet.
"Sod off, Potter."
"Get stuffed, Malfoy."
"After you, wanker."
"Oh, so that was you watching me in the showers, then? I'd been wondering about that."
"I wouldn't've watched even if there were anything to see."
"That's not what you said last night."
"Was this before or after I caught you running about after hours with the Mudblood?"
"I'm going to kill you."
"I'm quaking in my robes, really."
Malfoy is a miserable, sniveling git with a pinched nose and shifty eyes. His mouth is perpetually set in a sneer and he wouldn't be able to say something nice about anyone unless he were forced to do so at wand-point, and even then he might not deliver. In short, there's nothing to recommend Malfoy to anyone for any reason whatsoever, unless they were doing research on a book entitled Reasons that Purebloods Are Not All They're Cracked Up to Be and Why Intermarrying Is Bad.
Except.
Except that Malfoy looks quite fit lying on his back after Harry's knocked him off his broom. His hair's mussed, his Quidditch robes are all askew and the scowl on his face actually makes Harry want to lick him. Or lick his mouth. Harry's not sure. He's not going to stick around and find out either. There's a Snitch to catch and a match to win, and that's never going to happen with Harry hovering on his broom over Malfoy and staring when Malfoy licks at the blood at the corner of his mouth; so Harry's going to stop staring any moment now.
Really.
"What the hell were you playing at out there, Potter, you almost broke my nose!"
"It'd be an improvement as far as I can tell; you should be thanking me."
"An improvement? This from a four-eyed advertisement for Gladys Dalyrimple's Glamour-in-a-Jar? Let's see how you like my improvements then."
Harry knows that normal people don't tend to fancy people they loathe, and with good reason too -- it's very hard to wish someone dead while you're contemplating sticking your tongue down their throat. And it's only later, when Harry's leaving the infirmary with a Miss Sadie's Miracle De-Swelling Salve slathered over his right eye, that he wonders why he had to fancy Malfoy out of everyone he could choose from. Surely fancying someone like Terry Boot or Ron or even Pansy Parkinson would be less hazardous to his health.
"Why the long face, Potter? Did the Weasel turn you down again? Oh, that's right, he's gone off with Longbottom. Must be a bit hard to be the only virgin in your house."
"You would know, wouldn't you, Malfoy?"
"I'll have to take your word for it it's not as though I would touch you with someone else's wand."
"Don't flatter yourself, Malfoy."
"Flatter myself? I'm not the one making eyes across the Great Hall."
"I had indigestion."
"Tell yourself another one, Potty."
Harry knows he's not supposed to be charmed when Malfoy attempts to curse him in some bastardized version of Parselmouth, but he can't help himself. There are some things that have to come naturally or they won't come at all, so Harry knows Malfoy must've spent ages in the library trying to figure out how to translate and pronounce 'I'm going to kill you.'
The thing, though, is that Parselmouth doesn't follow literal translations and when Malfoy hissed "I'm going to thrill you" to him after Potions, Harry almost ran into the wall.
If Harry could choose someone to be attracted to; he'd like to think he would never choose someone like Malfoy. Surely he's not mad enough to need someone who hates him and aggravates him and makes him want to learn every curse in the Restricted Section, just to shut that pouting, sullen mouth. Except that Malfoy can be very appealing in his own, irritating way, and late at night when Neville's snoring away and Ron's tossed and turned until he's worn himself out, Harry stays up and wonders what it would be like if Malfoy loved him as much as he hates him. With all the time they spend fighting each other, if they could change things around that would really be something to see, but then Harry thinks about Lucius Malfoy in Azkaban and Sirius gone forever and he knows that some things just aren't on.
No matter how charming Malfoy may be.