Sam's long weekend continues.
The bus' movements weren't helping the situation at all, and Sam was starting to enjoy the feeling more than he wanted to. He tried to prevent her from moving too much by grabbing her waist, barely resisting the desire to press her hot body harder on his own.
His hands once again touching her, Jill was starting to feel light-headed. She didn't quite know why, but it felt so good just to feel her brother's muscular body pressed firmly against her. She could feel her panties dampening and thanked God that Sam was wearing jeans even on such a warm day. She instinctively spread her legs a bit more and started receiving vibrations from the bus' engine.
Sam's mind was now screaming in danger as he felt her relax on him with a deep sigh. His cock twitched in his pants when her weight pressed her mound harder on his crotch and he couldn't help his hands sliding down to her hips.
Wait... Was that...? Was she enjoying it? He couldn't see her face but he had heard that sound way too many times when watching porn to not recognize it. He didn't wait long before clenching his fingers on her hips to watch her reaction. She answered by cooing once more, causing Sam to lose the small portion of moral he had left. He slowly lifted his weight and thrust his hips forward pressing his dick harder against his little sister's pussy.
Jill was already lost in pleasure. She welcomed her brother's push by pressing her body tightly against him. She started moaning softly in his shoulder and couldn't help grabbing his neck. Each time he pushed against her, she answered by grinding on his bulge .
"His penis... my brother's... dick...", she finally realized, making her pussy squeeze itself with lust.
Sam's hands quickly slid down to claim once again his sister's hot and perky ass cheeks. He rubbed them, squeezed them, spread them apart and pressed her body tighter against him using this firmer grip. Her fingers running in his hair were emptying is mind and he felt his fingers crawl under the elastic of her panties. She tensed and grabbed his hair but didn't stop grinding on his hard cock with passion. Her skin was so soft and warm that he kept rubbing her ass for a while before his attention got back to the warmest spot inside his sister's underwear.
She held her breath when she felt him close to her pussy and shoved her face in his shoulder to moan loudly when she felt him brush directly on her wet cunt.
He couldn't believe how soaked she was and started rubbing her with his fingers, totally losing control on his actions. Jill's body got wild and she begun furiously humping her brother, crushing her clit on his cock.
His sister losing control quickly got Sam on the verge of coming. His middle finger had already found its way to the entrance of Jill's pussy and he started shoving it in and out of her hole angrily. Jill's eyes opened wide at the intrusion and she could only bite on his neck to prevent herself from screaming in the most powerful orgasm she had ever felt. It was all too much for Sam who began to shoot steaming hot sperm in his pants, while feeling her warm cunt squeezing his finger in quick spasms.
The young man was quicker to come back to his senses and his first reflex was to look around him, fearing that someone had noticed what just happened. Since nobody looked back, he could only conclude that they all had miraculously been oblivious to them. Jill was panting, her hands still around his neck while recovering from her massive orgasm.
He slowly slipped his finger out of her pussy and tried to make her stand in a less suspicious way.