She slaps him hard, finely manicured nails scraping across his pale face with a thunderous clap. He can't deny the pain but it doesn't hurt as it does with his father. Her reaction almost makes him relieved. No doubt proving that the rumors of her recent fight with Fred were true. Since her rejection the relationship between them had become turbulent at best and Draco longed for the day it would officially crash and burn. This is the most emotion she has shown towards him and good or bad he does not intend to let it go.
Even in her present state Angelina is still beautiful to him. Fred was a fool for having rejected her but Draco will not tell the woman this much. Instead he taunts her, tells her every one knew all along his heart was never hers to have but does not yet have the audacity to offer his own. It is better she is angry, better she feels it all now rather than later. It is with a bruised face but lightened heart he leaves her. He doesn't know what he is expecting but he knows he has yet to receive it.