Cowgirl Jemma

"I'd really like yo watch those new tits of yours bounce, Jemma," Josh said. "You're so proud of them and so grateful that I made you grow them, that showing them off really turns you on."

Jemma arched her back and gave her rack a shake, grinning.

"So let's roll mom over to the side and you can ride my cock cowgirl style," he said. "And you can just enjoy watching, Ronnie, and play with yourself if you like."

"I like..." Ronnie said weakly, them giggled. "I remember now, I like..."

The siblings helped their mother get situated, then Josh lay down, his dick pointing at the ceiling fan over his mother's bed. Jemma stood up on the bed, taking the opportunity to shake her new titties for her family, then straddled her brother and mounted him.

Josh sighed. His hot sister was impaled on his cock. It was a fantasy he'd harbored since puberty, but he never dreamed it woul ever happen. And he certainly never dreamed it would happen in their mother's bed, with her as am enthusiastic audience.

Jemma put her hands under her pendulous boobs and jiggled them as she grinned down at him. Ronnie gave a throaty chuckle.

"Is this good for you, Josh?" Jemma solicited.

"Very good, Jemma," he said. "You're very wet, aren't you? It feels so good to have me inside you."

"So good," she agreed. "So wet!"

"Lace your fingers behind your head and ride me when I say go, Jemma," he instructed. "Start slow, then get faster and faster, letting your titties bounce. The more they bounce, the closer you will get closer and closer to the most powerful orgasm of your life, but you can't cum until I say so. Got it?'

"Got it!' Jemma confirmed.

"Then go!" he said.

Jemma did as she was told, hands behind her head and working her hips to control her brother's joy stick. Josh looked up in amazement. Her new tits looked even better from this position. And the way her cunt slid along his shaft...he shuddered. How long could he stand this? Could he use his voice to control his own orgasm? Did his voice work on himself?

This wasn't the time to explore that. Better to explore what he could continue to do with Jemma.

"Use your cunt to keep me hard," he commanded. "Make me bigger and harder, but don't make me cum until I say."

His sister grunted her obedience and screwed up her face in concentration and somehow her vaginal canal changed and seemed so suck him deeper inside and then clench at him. It felt astounding. Was this what his father had done to his mother?

Ronnie moaned beside them, diddling her clit and squeezing a tit. No need to ask her now. She was busy enjoying herself. And so was Josh. Jemma picked up the pace and began riding hom harder, her tits goong from a gentle jiggling to a playful bounce. her cunt doing things that probably required differential calculus to understand.

Josh sighed and just let his sister fuck him as he lay there passively enjoying the view. Jemma's pace built and built and her little moans and gasps melded into groans and squeaks and the occasional 'oh fuck yes!' as she made a pogo stick out of her brother's cock and her cunt.

It was a miracle that she could stay upright, bouncing along like that. But no, it wasn't. Her body was doing what it had to to follow his directions. Tearing his eyes from her bounding rack, Josh could see her abs were now clearly defined. She had strengthened her core just so she could fuck him the way he had told her to!

And he had told her to go faster and faster, and so she did, and now her inflated jugs were smacking her in the face with every bounce, sweat showering down on her family as she screeched out out in mad arousal, eyes and mouth wide, dark hair a chaos, tits kinetic, **** to cum but unable to do so until he told her.

And Josh realized he wasn't sure he could speak. Whatever Jemma was doing to his cock was drawing so much blood into it that his vision was tunneling. He opened his mouth and moaned but couldn't manage words. His tongue felt heavy in his mouth.