He makes it so easy for me to hate him.

It starts with annoyance…

He splashes juice all over my freshly pressed shirt when he tries to hand me my favourite drink in the morning. How creative – he's noticed which juice I drink the most.

He spells my surname incorrectly when he sends me Chocolate Mint Cauldrons for Valentine's day. I don't like mint. Nor do I like being called Lily Evens.

Which progresses onto frustration…

He grins cockily when I turn him down that third winter, and I know he'll be back. And he is. Again and again and again and again. Some women find a hard head attractive. I'm not one of them.

He introduces himself as my future husband to my parents on the platform. My mother ruffles his hair and my father glances at me with a look that says "no boyfriends until you're sixty five". I receive an hour-long lecture on not trusting boys and the birds and the bees.

Which, in time, turns into infuriation…

He turns my best friend's hair a garish pink and tells him to get some shampoo – there are new species of lice developing in there. I get him into detention for a week. I also lend Sev some shampoo.

He hexes my first boyfriend's lips so that cold sores erupt all around them. "That'll stop you from any hanky panky, you dirty, dirty boy," he says to Davy, and winks at me. I have no problem making boils erupt in a place that will prevent him from sitting for a week.

But he makes it even easier for me to love him.

When he teaches that first year how to turn a match into a needle in a stern, fatherly voice, and he looks around quickly as if checking if the coast is clear, and ruffles the kid's hair.

When he turns to the long-legged, flighty fan girls after the last Gryffindor-Slytherin match he will ever play – and says, "Sorry girls, I've got a patrol now."

When he catches me studying him absently one Charms lesson and smiles timidly before turning away. I can't help but notice the strange but faint redness about his ears.

When he stops one evening in the Astronomy Tower and cradles my face like it is a priceless work of art and asks me one last time. His poignant eyes light up with stars when I nod.

When his fingers just graze mine as we walk through the corridors and he looks at me sideways and grins that crooked, mischievous smile.

When he wraps his arm around me and tucks me into his side in the light of the setting sun, his lips grazing my ear. "I love you, Evans." And he promises to do so until the Earth stops spinning.