"Lockhart's idea of a morale-booster became clear at breakfast time on February fourteenth. Harry hadn't had much sleep because of a late- running Quidditch practice the night before, and he hurried down to the Great Hall, slightly late. He thought, for a moment, that he'd walked through the wrong doors.
The walls were all covered with large, lurid pink flowers. Worse still, heart-shaped confetti was falling from the pale blue ceiling. Harry went over to the Gryffindor table, where Ron was sitting looking sickened, and Hermione seemed to have been overcome with giggles.
"What's going on?" Harry asked them, sitting down and wiping confetti off his bacon.
Ron pointed to the teachers' table, apparently too disgusted to speak. Lockhart, wearing lurid pink robes to match the decorations, was waving for silence. The teachers on either side of him were looking stony-faced. From where he sat, Harry could see a muscle going in Professor McGonagall's cheek. Snape looked as though someone had just fed him a large beaker of Skele-Gro.
"Happy Valentine's Day!" Lockhart shouted. "And may I thank the forty-six people who have so far sent me cards! Yes, I have taken the liberty of arranging this little surprise for you all - and it doesn't end here!"
Lockhart clapped his hands and through the doors to the entrance hall marched a dozen surly-looking dwarfs. Not just any dwarfs, however. Lockhart had them all wearing golden wings and carrying harps.
"My friendly, card-carrying cupids!" beamed Lockhart. "They will be roving around the school today delivering your valentines! And the fun doesn't stop here! I'm sure my colleagues will want to enter into the spirit of the occasion! Why not ask Professor Snape to show you how to whip up a Love Potion! And while you're at it, Professor Flitwick knows more about Entrancing Enchantments than any wizard I've ever met, the sly old dog!"
Professor Flitwick buried his face in his hands. Snape was looking as though the first person to ask him for a Love Potion would be force-fed poison"
Harry Potter and the Chamber of Secrets (Chapter twelve). J.K.Rowling