Snogging in the open wasn't wise for either of them. Dean would hear it from his friends, and if one of HER friends caught him, he'd probably be a pretty blatant Slytherin target.
But really, it was a bit worse for her. Dean would be thought of as daft for snogging someone who ostensibly hated him and everything he was. Daphne would be seen as a blood traitor slag, probably. Not that Dean believed that, but he knew it was a pretty big bloody risk for her to take.
He knew that, in the back of his mind, but it was hard to make himself pull away. She tasted nice and her lips were soft and her fingers were smooth and warm against his face. Dean leaned in closer, pressing the kiss deeper and slipping his hand from her neck, down her back to rest in the small of it.