Jennifer had been dozing when her grandfather used their bathroom. She assumed it was Jackson and only when Bill had opened her door had she realized it was him, viewing him through half closed eyes. She was still half-asleep and really did not want to wake up, so pretended she was fast asleep. She suddenly realized that she was almost naked and that her grandfather must be checking her out. She was surprised that she found herself liking that idea. After all, he was a very handsome man, and ever since she had started having sex she had enjoyed men looking at her.
The next evening, the entire family went to watch Jackson play softball. He had a homerun and two doubles, which was not unusual in slow-pitch softball. Afterward they stopped by the Dairy Queen. Jennifer excused herself to go to the bathroom. When she returned, her mother asked if she was okay. "Never better in my life," she grinned as she surreptitiously winked at her brother. He patted her knee under the table and smiled happily at her.
That night she crept into his bed. "Jackie! I've never been so glad to be on my period in my life!" she exclaimed, then kissed his lips. "And you know what? I'm so horny!"
Jackson kissed his sister, then their tongues were fucking in and out of each other's mouths. "I want to fuck you so bad, Jen!"
"Don't tempt me. I want it too, but I don't want to do it while I'm on my period," she whispered. "Can I suck your cock? I am dying to! I have not been in the mood for anything for two weeks."
They had done nothing sexual, beyond kissing, since they had last fucked. Two weeks. Jackson had only masturbated a couple of times. He had been so upset that he hadn't been his usual, perpetually-horny self. His sister was now between his legs, removing his underwear. His cock was completely engorged and eager for Jennifer to do whatever she wanted to do with him.
"Turn the light on," she demanded. "I want to see this monster! I love your cock, Big Brother!"
He reached and turned the bedside lamp on, revealing his swollen prick to his twin sister, who was already fondling and kissing and licking it. "Oh, Jackie! It is so beautiful! It just turns me on so FUCKING much!" she gasped as she licked the underside of it and wetly took the head into her mouth. She savored the feeling of her brother's glans inside her mouth. She was so hot for him. Her body craved him. She was already on the verge of orgasm from just looking at it and the realization that she, once again, had her own twin brother's cock inside her mouth. INCEST! The very word turned her on! She loved him and she desired him. More than that, she craved him. She wanted to fuck him so badly!
"Oh, Jen, you just don't know how good that feels!" he exulted. "Suck your Big Brother's cock, you gorgeous little slut!"
His words served to excite her even more. She attempted to go down on her brother as far as she could, copious amounts of saliva pouring from her mouth, wetting his thick, veiny cock. She reached and held his nuts, gently. She wanted their contents in her mouth. "Give me a big load, you stud!" she whispered as she sucked and moved her mouth up and down his cock.
"Stop, Jen. Let me suck your tits!" he begged. He knew he was about to erupt and he wanted it to last longer. Besides, he was hungry to feast on her lust-inciting breasts. He figured that she deserved pleasure as much, or more, than he did. He was severely limited in what he could do for her during her period, but he knew that her breasts were so sensitive that she sometimes had an orgasm when he sucked them.
The twins had no idea that their grandfather, not wanting to disturb their parents, had decided to come upstairs to use the bathroom. Better to wake up Jackson than to awaken the slumbering couple downstairs, he thought. He thought he heard something as he approached Jackson's door. The hallway was completely dark, but he could see a light under Jackson's door and felt his way to the door knob.
Carefully turning it, and peeking inside, he was met with the sight of his beautiful Jenny, his only granddaughter, removing her shirt, clad now only in a pair of bikini panties. Her breasts were magnificent, he thought. He had seen Shana's at that age, and the image was burned into his memory, but Jenny's were even better, firmer looking. She was obviously excited. Her nipples were hard as pebbles. Her body was slender and her shape was perfect. He could even see her abdominal muscles. She was a work of art. Never had he ever seen a girl - a woman - who was this perfect.
What was she doing? What? She was in the bed with her brother - her twin - she was naked with her own brother? She lay down and Jackson rolled to his side. His grandfather could now see that Jackson was naked and that his young, thick cock was fully hard. This was horrible! This had to be stopped. He would burst in and stop this right now! But then he saw Jackson kiss his sister, no brotherly kiss, but a kiss of passion. They were sucking tongues! Bill felt his cock stirring in his pants. He would just see what happened before he broke this awful thing up. Then Jackson was kissing his sister's bountiful breasts and she was arching her body up to him. He was licking, and then sucking her nipples! Bill had never seen anything so salacious in his life.
"Big Brother, they're sore. Be gentle. They love you so much," she moaned as he gently squeezed them as he continued to suck on them. It was obvious that he knew what he was doing and it was obvious that this was not the twins' first time to do this. Jackson reached between his sister's legs and began to rub, very tentatively over the top of her panties. She reached down and put his hand where she wanted it and whispered, "Right there! Make me cum!"
Bill couldn't take it any longer. He reached inside his pajama pants and took his cock out. The head was already smeared with pre-cum, something that rarely ever happened to him anymore. He watched as his grandson continued to suck his own sister's breasts and to rub on her hot little cunt. Bill, of course, couldn't blame him. Who could possibly turn this girl down? She would make a dead man hard. She, single-handedly, could put an end to male homosexuality!
She arched her lower body toward Jackson's hand, as he continued to rub her through her panties and mini-pad. He went from one breast to the other, back and forth, gently kissing and licking her hardened nipples. "Ohhhhhh! Yesssssss! I am cummmmmmmmmmmmming!" she moaned. Bill stroked his cock, wishing he had a handkerchief or some Kleenex or something.
The twins kissed, tenderly, like lovers, then Jennifer got on her knees and kissed Jackson's balls as she hefted them. "They feel so full!" she said, teasingly. "Do you have a big load for your little sister? I want it ALL!"
Bill could barely contain his own moan when he heard his innocent little Jenny say these words. He could clearly see her in profile, her generous breasts projected from her body like missiles as she leaned over to kiss her brother's balls, then lick her way up to the head of his cock. He could see an expression of sheer rapture on his grandson's face. Jennifer's face was more beautiful than ever as she licked around the corona of her twin's swollen penis. Then she kissed and licked at his frenulum, knowing that it was his most sensitive spot. This girl clearly loved sucking a cock.
"I want to fuck you so bad!" she moaned as she looked into his face while she stroked his saliva-wet shaft. "I can't wait until we can fuck again!" With that she lowered her mouth over halfway down his considerable thickness. She seemed to relish it, her eyes closed as if in ecstasy.
"Oh, Baby Sister," Bill heard him gasp. "I'm cumming!"
Bill saw Jennifer take Jackson's shaft in her hand and pump it as she kept her mouth open wide. He could tell when the first blasts of cum shot into her mouth as she moved her head slightly back, then opened her mouth wider. After a few seconds she moved her face back and he could see her, purposely aiming his grandson's spewing cock at her face. Huge wads of white cum were landing on her beautiful face as she moved her hand and her face so that it was completely covered. As the spurts diminished, she dipped her head and took the head of his cock into her mouth. She kept it there until Jackson gently pushed her head up. Her smiling face was dripping with her brother's warm load. She opened her mouth and leaned forward to give Jackson a look at the contents, then swallowed.
Bill was on the verge of cumming, but thought it best to wait until he was back downstairs. He certainly didn't want to leave any evidence that he had been here. He saw his granddaughter wiping cum from her face and licking it off of her fingers, slowly, as her brother watched her.