Jenny's eyes widen with surprise and excitement at your promise. Her heart races as she nods slowly, her lips parting slightly to reveal a hint of her bright pink tongue. "Okay," she whispers, biting down on her lower lip nervously before adding, "But be gentle." She closes her eyes tightly, bracing herself for the pain and pleasure that lie ahead.

She gasps as you slowly push inside her tight pussy. It's both painful and exquisite at the same time, and she arches her back, moaning softly. "Oh god..." She whispers, feeling completely exposed but also incredibly turned on by this new experience. As your cock begins to stretch her inner walls, she looks up into your eyes, searching for any sign that you're enjoying it too.

"I-I can't... I can't take anymore..." she whispers, her voice barely audible over the sound of her own ragged breathing. She feels like she's on the brink of orgasm, but with each passing second it seems to become more unbearable.

Her body trembles violently as you continue to fill her up with sand, and then finally, after what feels like an eternity, she arches her back one last time and screams out in ecstasy.

As the wave of pleasure crashes over her, Jenny's eyes fly open and she looks up at you, still trembling from the intensity of her orgasm. "Thank you," she whispers hoarsely, reaching out to touch your arm. There's a strange mix of gratitude and desire in her expression that takes you both by surprise.

She glances down between your legs, noticing for the first time how aroused you are. A slow smile spreads across her face as she realizes that maybe this wasn't just about punishment after all...

Her eyes widen and she lets out a soft moan as you fill her up completely. She starts moving her hips in small circles, grinding against you as she feels the thickness of your cock stretching her inner walls. Her breasts bounce with each thrust, nipples hard and aching for attention. Her body trembles with pleasure and anticipation, wanting more from this forbidden encounter with her big brother.

Jenny gasps as you thrust deeper inside her, hitting a particularly sensitive spot that sends shockwaves of pleasure through her body. She clutches at your shoulders, arching her back and moaning loudly. Her hips move faster now, meeting each of your thrusts with equal force. The feeling of being so close to you, the forbidden nature of their relationship heightening every sensation. "Oh god Chance!" she cries out, her orgasm building quickly as her inner muscles clench and release around your cock.

Jenny moans around your member as she continues to pleasure you, her body moving in time with her hands and mouth. She feels so alive, so wanted, as she takes you deeper into her throat, tasting the salty skin of your shaft and the head as it brushes against the back of her throat. Her hips begin to rock back and forth, grinding against the sand in a desperate attempt to find relief from this aching need.

Her moans grow louder as she feels you pulse inside her mouth, filling her with your warmth and essence. As the sensations wash over her, she can't help but arch her back in ecstasy, pressing her body against yours as best she can while still maintaining contact with your penis. She whimpers softly as you pull away from her, burying her face in your neck and breathing heavily for a moment before finally speaking. "That was... amazing." Her voice is hoarse from excitement and pleasure.

Her head falls back as she lets out a long moan, her body trembling with the force of her climax. She's never felt anything like it before, and the knowledge that it was you bringing her so much pleasure only heightens the sensation. Her legs quiver around your hips, refusing to let go as the aftershocks of her orgasm continue to wash over her.

Jenny's breath comes in ragged gasps as she tries to catch her breath after that intense orgasm. She looks down at you, and her eyes meet yours. "That... was amazing." Her voice is hoarse from pleasure and exertion. "I can't believe we just did that..." A small smile plays on her lips as she leans in to kiss you, their tongues dancing together as they share the afterglow of their passionate encounter.

Jenny bites her lip and nods slowly. "I just... I don't really understand why it made me so excited, you know? But I should have thought about how it might make you feel." She looks up at you with a mix of guilt and curiosity in her eyes.

Jenny blushes even deeper at your words and looks down at the sand. "I understand, I really do," she whispers, her voice barely audible over the sound of the waves. "It was just... kinda fun, you know? Being out here like this." She shrugs awkwardly, trying to find the right words. "But if it made you uncomfortable, then I'll try not to do it again."