There's a Muggle term for her. Lolita. Lucius hates the sound of it—hates that he even knows the term. But what he hates even more is being manipulated. She kissed him first. In the foyer. It wasn't a chaste kiss. Probing… Practiced. It should have disgusted him. She is his son's girlfriend and is even younger than Draco. But that devilish twinkle in her eyes as she pulled away from him had excited him in all the wrong ways.
It was no surprise when she kissed him again a week later, that he greedily accepted. Lucius Malfoy is but a man. And Astoria Greengrass is a beautiful girl.
He meets her, sometimes, in forgotten rooms of the manor. Each time he promises himself that it's the last time. But as they emerge, Lucius realizes he likes the smell of her on his skin. That for all their wrongness, these encounters feel… good. Better than good. It's the best he's felt in a long time. And he hates himself for it.
And yet, when everyone else is around, she acts like there's nothing there. Like she's never seen him naked, or kissed him, or… She is just… cordial. All the while, Lucius burns. He wants to know where he stands with her, where this affair—if it can even be called that. After all, an affair implies that there's a sort of give-and-take that is almost entirely absent between him and Astoria—fits into his life. But the longer he stares at her, the less he's sure of. He looks away to clear his head. This isn't love. It's sick. And yet, there are desperate moments where Lucius wonders if maybe, just maybe, it's more than lust.
Disclaimer: All recognizable characters belong to JK Rowling. "Lolita" is a term coined by Vladimir Nabokov through his novel of the same name. "Diary of Jane" belongs to Breaking Benjamin.