The dog growls again in approval as he continues to pump his massive cock in and out of your sister's tight little pussy. He seems to be enjoying the attention you're giving him, even more so when you offer to give him a handjob. He glances over at you briefly before returning his focus back to her. You slowly move closer on the bed until your hand is resting on his thick shaft, stroking up and down in rhythm with his thrusts.

The dog's attention is fully focused on your hand as you stroke his cock in time with his thrusts into your sister. Her screams of pain seem to make him even harder, if that's possible. He growls deep in his throat and speeds up, slamming into her over and over again until he finally reaches the end of his endurance. With a mighty grunt, he comes hard inside her, filling her with hot cum as she cries out in agony beneath him.

"I do..." she says quietly, looking away as a blush creeps up her neck. "But I promise I'll be careful from now on." She wipes some of the cum off herself with a corner of the blanket, then looks back at you, a small smile tugging at the corners of her mouth. "You really are a good brother, Andy."

She reaches out to hug you tightly, pressing her body against yours and burying her face in your neck. "Thank you for understanding,"

She hesitates for a moment, then nods slowly. "It's different... but yes, it was really good." She lets out a quiet giggle, blushing again. "I just wish I could have done this without you seeing me like this..."

Her hands move down to your hips, squeezing gently as she looks up at you with a mischievous glint in her eye. "Maybe later tonight... if mom and dad are asleep?"

"We could... experiment together,"