Are you kidding? As if she would decline this invitation!

The cum he swallowed had satisfied a deep need in Adam (and made his belly swell a little). His lust was still burning, his pussy still slick and wet, but he did not really care right now.

Sarah, on the other hand, was still rock hard and throbbing, despite just having cum what seemed like a gallon to her. How could she resist the juicy, wet pussy right in front of her? She quickly stripped herself of her shirt and pants and stepped closer to the bed. Panting, she gripped her thick meat and lined it up with her brother's inviting snatch. Then, with one smooth thrust, she penetrated him up to the hilt, made easy by how wet his previous orgasm and all the cocksucking had made him.

It was exquisite - tight, wet and warm. She did not move for a second, just revelling in the feeling Adam's pussy gave her. Adam himself did a sharp intake of breath and gripped the sheets tight with both hands. His eyes shot open, unfocused. He felt so full! It felt so good how Sarah's cockhead gently pushed against the entrance to his womb. Right now, he did not care that he was a guy, that he had a pussy, that his nipples did things no male nipples should do or that it was a dick that was giving him so much pleasure. He felt full. He felt fulfilled.

Then, Sarah startet moving. Pistoning back and forth, the feeling intensified. Her fat tip scraped along the insides of his pussy, the shaft stretched his pussy lips deliciously and her hands on his hips squeezed him. In just a few strokes, he felt his orgasm building, his breath coming in **** gasps. Sarah's hand then moved to the little swollen button on top of his stretched slit, lightly touching it.

This sent him careening over the edge. Howling with pleasure, he came hard, legs shaking, toes curling, back arching. His eyes were screwed shut in ecstasy.

Sarah meanwhile demonstrated remarkable dick discipline. Although her just having cum definitely was a factor, her short, quick jabs served to prolong his orgasm and forestall hers, despite Adam's pussy clamping around her like a vice.

On Adam's upper body, meanwhile, the overdose of Growth-X enhanced cum began having an effect. Under his puckered nipples, flesh started to swell, slowly, but surely. With every one of Sarah's thrusts, more jiggle was added to the little mounds, barely noticeable at first, but when Sarah realized what was happening to her brother's bust, she could not hold back anymore. She could not tell whether it was a long-buried fetish for breast expansion or her newly grown dick, but the sight drove her wild. She lay down on top of Adam, her hard nipples brushing over his with every one of her long, hard thrusts. His swelling boobs began pressing into hers, pushing them apart little by little, slowly spilling down Adam's ribcage. He himself was just coming down from his first orgasm, but the stimulation of his growing boobs, Sarah's nipples on his and the big, fat cock in his dripping cunt led to his arousal mounting quickly.

Sarah, too, could not hold her orgasm back any longer. Her brother's moaning face in front of her did not help matters much, either. Her pistoning quickly became erratic and with one last, deep thrust, she exploded inside of him, painting his womb with her seed. The feeling of hot jizz streaming inside of him gave Adam his third orgasm of the day.

Panting, Sarah rolled off of him, her seed dripping out of his thoroughly serviced cunt and coating her massive, slowly softening member.