She sees him in Diagon Alley three months after the war has ended, and for just a minute, she forgets.
"Draco!" His name escapes her lips before she has time to think, before she remembers that he and his family are disgraced whichever way you look at it.
From a Pureblood point of view, he let the side down, not fighting at the last. From the point of view of the new regime - forgiving and liberal though it is trying to be - he is a traitor and an attempted murderer who is lucky not to be sharing a cell in Azkaban with his father.
Pansy would do well to leave him alone, and by the time he has registered her call and turned to see her, she has remembered it, with a sinking feeling in her chest and a hard knot forming in her stomach. She must forget any feelings she ever had for him. He is unsuitable for her now. (And the irony that he is now beneath her notice does not escape her, even as she is thinking what in Salazar's name she is to say.)
He turns and stares at her, the expression on his face unreadable. She has had time now to prepare her line.
"You are a traitor and a coward," she says, "I wish I had never known you," and her voice is hard and does not shake. She turns from him as her lips begin to tremble and the tears overflow, but she hears his reply.
"The truth is, Pansy, I never cared for you."
She believes him. And that makes her cry harder.