(1) Classes with No Class, just Ass

In order to have every Witch available while also making sure nothing interfered with the Competitions, Headmaster Riddle had every Witch, both Student and Teacher, fitted with a Chastity Cage a week into the School Year or after giving birth It would only be removed when the other Schools arrived and Champions Chosen. It was... Unpopular. But they still had oral and anal.

Transfiguration
"No Miss Brown, we will not be learning to turn your magic-resistant cage into edible underwear. No, we will not be learning how to transfigure larger genitals. No you may not fornicate in my Class."

Care of Magical Creatures
"Well done Miss Chang!" Hagrid boomed from the crater he had formed from impacting the ground. " Ye're the Firs' o' me Holstaurs to still be able to use her Wand!"

Cho was too angry. She needed some cock in her pussy! Professor Hagrid said he had a way. Turned out his way was to turn her into a brainless, bovine, bimbo! If she was unable to use a Wand, she'd be unable to remain a Student and this could have the cage removed. That was not what she wanted!

Thankfully, she still could use her Wand. But now she was hornier than ever with horns, a tail, and massive udders!

Fuck, her language was changing too!

Herbology
Cedric Diggory hadn't offered to work as a Teaching Assistant to score extra points for his Jerbology Exams. He wanted to shove his dick between the biggest tits in Hufflepuff. Susan Bones might be the niece of Amelia Bones, and trained to be able to Duel the nastiest criminals to hold a Wand, but a dark secret of the Bones Family was they needed to have their pussy fucked regularly when they came of age. As it was, Susan was an easy way and her month of sexual frustration was causing her already epicly big tits to be close to incapacitating size.

Divination
"As you can see Students, by wiping a thin layer of seven on the ball, you can observe some of the kinks and perversions of the doner. I must also warn you all; do not try any shortcuts with this, all attempts so far have not given a Witch deeper insights into a man's desires, only embedded those kinks and a desire to obey into the poor Witch's mind."

Muggle Studies
"This is actually quite helpful in some of what we'll cover!" The Witches whined as manages appeared on their wrists just as Professor Pettigrew vanished their Chastity Cages.

"A growing niche in Muggle Pornography is Anal Only, where women refuse to have their pussies fucked." The Witches all wailed as they realised they weren't going to get to play with their aching holes. "At most, they will slap it and invite others to slap it. I'll randomly command the pancakes to do so. The first to cum from anal, gets points for their House. Begin!"

History of Magic
Hermione have birth two days into the new school year. When she heard about the Cages, she knew she wanted one in he as soon as her babies were out. Or Ruby would make sure she was knocked up. But Madame Pomfrey insisted she let her body heal first. It as supposed to go on the next day. She'd been careful and kept clear of Ruby, who was a little distracted by her Mum, her Dad, and her Girlfriend. Hermione made the mistake of forgetting she was "friends" with Moaning Muggle since a Polyjuice Potion back in her Second Year. So when Myrtle went looking for fertile sluts for her boyfriend Sirius Black... Hermione never imagined her womb getting fisted... In reverse.

Hermione woke the next day to the sight of a smiling Myrtle, a happy Professor Black, and a hysterically laughing Ruby Evans. Curses.

Defence Against the Dark Arts
"In less enlightened times... Werewolves were considered beneath Human. So despite their known prowess in bed an their desirable libidos, they could be recruited as a Task in the TriWitch Tournaments.

Lupin roared under the moonlight through his muzzle as he shoved his knotted dick deep into Pansy Parkinson. The Slytherin Cumdump since a bad break-up with Draco Malfoy, she was chosen to assist she to getting her womb stuffed with Werewolf nut butter. Despite the humiliation, her pregnancy made her more popular because she got to keep her pussy unsaved and so she was getting stuffed a lot.

Fuck, her class schedule had gotten fucked by having to attend this class for every year group over eighteen and she felt she was getting dangerously close to becoming addicted to Werewolves. She didn't want to be a Knot Slut!

What Next?
Option 1- Ruby introducing her girlfriend to her parents
Option 2- Durmstrang Arrival
Option 3- Beauxbatons Arrival
Option X- Open to Suggestions