Lust Spitter.

One plant that only grew in tropical areas was the the Lust Spitter Flower. Named because it did just that. The potent plant would fire a powerful aphrodisiac that was the the key ingredient for one of the most power lust potions on the planet.

But the potion actually lessened the effects because a full dose was so powerful it would send even the strongest wizard or witch into a frenzy of sexual desire making them liable to shag for hours and hours.

Hermione had noted those flowers were on the island and knew what to look for, but an uneven step was not in her calculation.

"Ah!" she let out as she lost her footing and landed behind a group of trees and down a small hill.

"Hermione?!" Harry rushed over. He stood at the top of the hill and was about to jump down to her.

"Im all right. Just fell." She sat up.

She gabbed her wand from the ground and that was when she saw the flowers. Right in front of her.

"Harry stay there!" she said in a loud whisper.

"What? What is it?!"

"Dont yell." She hissed and motioned to the flower.

Then the center opened and Hermione didn't have time to get a ward up as the potent liquid sprayed all over her face.

"Ah..." She gasped and her mind went crazy. Then her body reacted by her already aroused state shot into orbit.

She managed to get to her feet and stumbled to the water. She had to wash this off! If Harry smelt it too...

She dove in and tried to clean but it did nothing for the chemicals already in her system.

"Hermione?" Harry came down to the water. "Are you okay?" He came closer.

Hermione turned to see his long cock swaying towards her. Her eyes were locked in it as the lust overwhelmed her senses.

"Hermione?" Harry had seen that look before from his gorgeous girlfriend but this was a lot more animalistic than he was use to.

Hermione began moving through the water. The whole time her eyes were glued to his cock. Her rational mind was trying to fight but that part was quickly losing to the need to be shagged senseless by her boyfriend.