They prepare spiked sweets for Pansy Parkinson

(Fred & George dropped out of Hogwarts, and in this reality, they are able to come back the next year to finish. Harry, Hermoine, and Ron's 7th year class)

Fred and George had developed a number of magical candies. Candies that caused puking pustules, fake mumps, etc, but their latest triumph is their best. They have developed a candy that is both a super-charged aphrodisiac and a Spanish fly. Whoever ate it would have an itchy pussy and anus and crave sex to relieve the itch, not caring about anything else.

They had experimented on a couple of Muggle girls at a Muggle university and saw it turn them into shameless submissive sluts.

The candies just look like chocolate stars.

They settle on their target: 7th year Slytherin student Pansy Parkinson. Like most Slytherin girls, she’s a smug bitch.

Fred and George wrap the chocolates in a fancy package and write “To Pansy. Thanks for being a Slytherin Champion!” on a card.

The next question is how, when, and where to get it to her.