Vines and tentacles

Neville found a spell that if cast on a certain vine would cause the vine to grow and produce multiple tendrils that would obey the spell caster. He decides to surprise Luna with it. He would toss a seed of the vine under her bed, and she would wake up surrounded by lovely flowers.

Neville goes into the woods and finds the vine. He plucks a seed pod and returns back to the school. In the Room of Requirement, he casts his spell.

That night, he sneaks into Luna's room and finds her fast asleep in her bed. She’s in fetal position with the covers pulled up to her neck. He whispers some words to the seed and tosses it under her bed before hiding in a closet and peeking out.

Neville watches as tendrils emerge from under the bed. The ends hook the covers and pull them off the sleeping cutie. Neville wonders where the flowers are. The tendrils reveal Luna's silk pajama shorts and halter top.

Neville is shocked when four tendrils wrap themselves around Luna's wrists and ankles, then another worms over to her mouth and gags her. The vines flip her on her back and hold her spread-eagled. She wakes up and cannot move. Despite this not being what Neville had planned, he finds himself growing aroused. The tendrils pull her shorts down and an expose her neatly trimmed white-blonde bush.

A moment later, thick long tendrils are fucking Luna's pussy and anus. The tendrils have grown to be as big around as a human cock and twice as long. Luna struggles but can not move nor speak.

Neville cannot believe this. Not only did the spell not work out as a present to Luna, the vine is **** her pussy and and anus, and instead of rushing to help her, Neville slides a hand down his pants and starts stroking his cock.