They were in that position when Hermione got hungry studying and decided to go to the kitchens for a snack. Because there was a kitchen in the Head student rooms Hermione decided not change out of the tank top and boy short underwear that she was wearing. Having placed a silencing spell on her door earlier, she didn't hear the grunts and moans coming from the common room until she began to open the door. As soon as the sound hit her Hermione's mouth fell open and her mind started racing. 'Do I close the door now? Did they hear me? But I'm hungry! But he has the common room for today. We need to change those rules. I wonder if I can see anything? Why am I looking?' Her curiosity won out over her nerves and propriety and she pressed her face to the small opening of her doorway to peek out.
Her mouth fell open as she watched Malfoy pounding into Lavender. Lavender's face was pressed against the desk and her eyes were clenched shut in a combination of pain and pleasure. Malfoy removed his hand from below Lavender's body and he threw his head back, his eyes closed with satisfaction. Hermione felt her nipples harden beneath her top and warmth jolt her cunt as she watched.
Hermione's face blushed and she fell back against the wall next to the door. 'That is so…' she searched for the perfect word to describe the scene 'disgusting…no, intriguing…no stimulating.' She crawled to the crack in the door again in time to see Malfoy pull out of Lavender just long enough to grab her hips and flip her over on the desk.
Lavender's body was coated in sweat and limp as Malfoy manipulated her into a position where he could penetrate her again. Malfoy grabbed Lavender's ankles and threw them over his shoulders as he reentered her cunt easily in one fluid thrust.
'Hot' Hermione thought to herself. 'That is so hot.' Without really thinking about it, she began to trace her fingers over her collarbone and down between her breasts. She watched Lavender's breasts bouncing as Malfoy ground his pelvis into hers. Hermione watched as Lavender pinched and pulled at her taut nipples, her whines and whimpers reverberating around the common room.
Hermione mimicked Lavender's motions on her own hard tips and let out a low moan at the sensation and the new surge of warmth in her knickers. She watched open-mouthed as Malfoy reached his hand to Lavender's clit and began to rub in quick hard circles. He grinned as Lavender arched her back and screamed in response.
Hermione moved the fingers of her other hand to her own clit and found herself extremely wet. "Fuck" she murmured as she began to rub slow circles around her sensitive core with her thumb. She slid her middle finger into her soaking cunt and, finding that unsatisfying, added her ring finger as well. "Fuck…" she said again, pinching harder at her nipple and adding more pressure onto her clit as her eyes closed and she felt waves of pleasure wash over her. Hermione sped up her fingers as she opened her eyes to look at the couple again.
Her gaze moved over Lavender's writhing body and Malfoy's straining muscles to his face. Her brown eyes met his dark ones and Malfoy's grin was the largest she had ever seen on his ever-sneering face. "Fuck!" she exclaimed for a third time, although this time not out of pleasure.
Malfoy winked and continued to thrust into Lavender, who noticed nothing, her eyes still shut as she moaned and squirmed beneath him. Hermione's brain raced as she thought of what to do. 'I should leave; maybe I can deny it later? Who am I kidding; Malfoy knows exactly what I'm doing. There's no way I could live this down. He has all the power! He caught me touching myself! He knows I am enjoying watching him! What would Malfoy do in this situation? He never seems to care what other people think. Never seems to care what I think! I wish I could be that confident.' At that thought, an idea occurred to her. 'Oh well, fake it till you make it.' She returned Malfoy's wink and sped up her fingers.