Demi suddenly opened the door and saw you masturbating. Her expression suddenly became surprised and embarrassed. She turned around quickly, her face flushed, and she looked a little overwhelmed. She whispered "Oh, no, I'm sorry, I didn't mean to... um, disturb you. "

There was a hint of nervousness and embarrassment in her voice. She quickly closed the door and stood at the door with shame on her face.

Still facing the door, Demi's cheeks burn even brighter as she hears the rhythmic stroking increasing in speed. She bites her lip, trying to suppress the curiosity that's starting to overcome her embarrassment. "I... I should really go..." she mutters, but her feet stay firmly planted in place, as if some unseen force is keeping her there. "This is so awkward..."

Demi flinches at the sound of her name, her heart pounding in her chest. She can't help but glance back over her shoulder, just in time to see Francisco's body tense and his hand move frantically. A moment later, she hears him cry out and she quickly turns away again, her face now bright red. "Oh my God..." she breathes, her voice barely above a whisper. Her mind races, imagining the sight she just witnessed. Francisco's cock is much bigger than her boyfriend's, and the thought sends an unexpected shiver down her spine. She shakes her head, trying to clear the inappropriate thoughts. "This is so wrong..."

Demi takes a deep breath, trying to gather her courage. She slowly turns back around, peeking over her shoulder at her brother. She bites her lip as she sees the cum dripping down his shaft. She looks away quickly, her face still bright red. "I'm... I'm gonna go..." she says, her voice shaking slightly. But she doesn't move, instead staring at the wall, her mind racing with thoughts she knows she shouldn't be having. Her curiosity is starting to win out over her embarrassment and she can't help but wonder what it would feel like to touch him, to feel that big cock in her hand.

Demi's eyes keep flicking back to Francisco, unable to resist the temptation to steal glances at his still-hard cock glistening with cum. She imagines what it would be like to wrap her hand around it, to feel it twitch and throb in her grip. Her heart races as she feels a growing heat between her legs. She knows it's wrong, but the desire is too strong to ignore. "Fuck, this is so messed up..." she mutters under her breath, her voice trembling with a mix of nerves and excitement. She takes a step closer, then another, until she's standing right behind Francisco. She can smell the musky scent of his arousal, and it makes her head spin. Her hand reaches out, hovering just inches above his cock, trembling with the effort it takes to resist the urge to touch him.

Startled by Francisco's sudden exclamation, Demi yanks her hand back as if she's been burned. Her eyes go wide with shock and she takes a quick step back, her face flushing an even deeper shade of red. "I-I'm sorry! I don't know what came over me! I shouldn't have... I shouldn't have done that!" She stumbles over her words, embarrassment and confusion warring within her. She feels a pang of guilt for betraying her boyfriend, but she can't deny the strong pull of desire she feels towards her brother. "This is so wrong, I need to go... I need to think..." With that, she turns and flees the room, leaving Francisco alone with his thoughts and his still-hard cock.

Demi freezes at the sound of Francisco's moan, her heart pounding in her ears. She can't believe she actually touched him, can't believe how good it felt to have his hard cock in her hand. She takes a deep breath, trying to steady herself. "I... I should really go..." she says again, her voice barely a whisper. But her feet remain rooted to the spot, as if they have a mind of their own. She glances back over her shoulder at Francisco, her eyes lingering on his cock, still slick with cum. She licks her lips, imagining the taste, the feel of it in her mouth. She shakes her head, trying to clear the dirty thoughts. "Fuck, what am I doing? This is so wrong..."

Demi can't help but gasp as she feels Francisco's cock twitch in her hand. Her heart races as she realizes she's still touching him, still holding his hard shaft. She looks up at him, her eyes wide with a mix of fear and desire. "I... I'm sorry, I didn't mean to..." she stammers, but she doesn't pull away. Instead, she finds herself gently stroking him, feeling the smooth skin and the hard muscle beneath. She bites her lip, trying to suppress a moan as she imagines what it would feel like inside her. "This is so wrong, but... it feels so good..." She looks up at him, her eyes pleading for forgiveness, for guidance. She knows she shouldn't be doing this, but she can't seem to stop herself.

Demi gasps as Francisco's cock twitches and thrusts into her hand, seeking more of her touch. Her eyes widen in surprise and she feels a jolt of electricity run through her body at the sensation. She glances down at his hard shaft, slick with cum, and she licks her lips. Her curiosity and desire are growing stronger by the second, overriding her initial embarrassment and hesitation. "Oh god... it's so big..." she whispers, barely audible. Her hand starts to move on its own, gently stroking him, feeling the weight of him in her palm. She looks back up at Francisco, her eyes filled with a mix of fear and longing. "I... I shouldn't be doing this... but it feels so good... I can't stop..."