Disclaimer: Harry Potter belongs to J.K. Rowling and her publishers; no money is being made.
She doesn't know what precisely it is that draws her to him.
Maybe it's the forbidden. Her family would be devastated to know she's shagging a Malfoy; especially her father would be livid. The idea of her parents or brothers walking in on them, seeing her like this, gets her as hot and wet as Scorpius' fingers and tongue. The allure of the forbidden certainly has a part in it.
Maybe it's Scorpius himself. He's so eager to please, such a sweet boy at barely fifteen, all smiles and soft skin and silky blond hair. She never gets enough of touching. Later, they'll lie together for a while, she'll pet his hair like she used to do with her own children before they thought they were too old for it, and he will look at her with an admiration and trust that make waiting until the next time seem nearly impossible. Yes, it's Scorpius as well – she wouldn't want any other boy.
Or maybe it's that she isn't as blind and stupid as Harry appears to believe. She does notice the glances between him and Draco, the hints at smiles when they think nobody is watching, and the way Harry smells sometimes when he comes home at night. He smells just like Scorpius.
"Mrs Potter?"
Ginny blinks, distracted from her thoughts, and finds herself looking at grey eyes in a flushed face.
"Am I doing something wrong?"
He looks confused, worried even. She loves how much he seeks her approval each time.
"No." She smiles. "No, you're perfect. Go on."
Scorpius smiles back and lowers his head back between her thighs, and soon, she doesn't care all that much why precisely she wants this.
If Harry can have the father, his wife can have the son.