Harry Potter and the Half-Blood Prince, a’la the Winged Pig

“Do you or do you not date a boy named Dean Thomas?”
Ginny giggled. “Well… ‘Date’ might be the wrong word… Dean… Dean…” Her gaze stumbled over the rigid mass of zucchini dominating the tray in the center of the table. “Oh yes. Dean.”
Harry sighed as the dulcid voice of his lady love permeated his consciousness. His addled eyes soaked in the vision of her beauty. As always, Ginny was wearing her Hogwarts uniform. His besotted stare did not go unnoticed.
“Sweetheart, I know you are trying to save us money… But really. You are still wearing your uniform from five years ago.” Mrs. Weasley’s voice was strained.
“No worries there. Madame Malkin is so very eager to take my measurements.” Ginny pushed her finger into the chocolate pudding and began to suck on it, staring at Harry’s rapidly reddening face. “She said to just come by after she closes, come by and we can have the dressing rooms all to ourselves. She says I have the most beautiful hair… Can I just accept a little present from Madame Malkin, daddy?”
“Uhm… well… Yes…. Madame Malkin…” Mr. Weasley’s voice trailed off into the wild blue yonder. He looked distinctly uncomfortable.
Mrs. Weasley closed her eyes, her face flushed with old memories. “Oh… Yessss…. Madame Malkin…” she weakly leaned against the refrigerator.
Ron clapped his hands together to break the tension. “Well! Have some more cake, Hermione!” With a flourish, he produced a stash of suspiciously shiny brown slices on a moss green plate from beneath the table. Ron grabbed a slice of rich chocolate cake and pushed it into her mouth. “Chew and swallow, Hermione!”
Her eyes rapidly glazing over, she meekly nodded. “Yesh mashter.” She muttered in between helpings of dessert.
“Well, Ron, at least you have been paying attention in Potions!” enthused Mrs. Weasley, staring at Ron’s report card. There is even a notation from Professor Snape congratulating you on your Potion of Obsessive Lust. He also says you have a firm ass…” Mrs. Weasley shook her head as if trying to clear cobwebs.
“I don’t trust Snape.” Growled Harry. To chase away his unease he opened the Half-Prince’s book of Advanced Potion Making. The Prince used a special code to denote his ownership of the precious volume – Harry has been dying to decode it. He scanned the mysterious line one more time before closing the book and resuming his dinner.

“Property of Severus Snape. Don’t touch my shit, Potter, or I will kill the Headmaster.”

What could the words mean? Who is the Half Blood Prince? Why the thinly disguised code? Why put the secret of the book into such an incomprehensible drivel?