Bill snuck into the room of his 16-year old stepsister. As usual both their parents were at their night jobs. It was a warm night and Alice was sleeping on her back, naked, and legs akimbo.

She was a cock-inspiring sight. She had firm tits with long nipples, a shapely ass and a beautiful cunt with trimmed bush. Bill had only hoped to sneak a peek at her, but the sight of her naked body made his jizz boil.

He dropped his pajama bottoms and standing naked started stroking his cock. It was pretty good sized for a 13-year old and quickly erupted. He had expected to collect the jizz in his hand, but the effect of his stepsister's nakedness caused his jizz to shoot passed his cupped hand and splatter on the shapely tits before him.

Bill knew he'd better run, but he was unable to stop pumping before the last drops of his goo were exhausted. And in that short time he saw before him something that changed his life forever.

She didn't awake! She began to moan. The moans became louder and she began to writhe. Still asleep her hand crept to her cunt and she began to stroke her clit. She started having orgasm after orgasm in a rising crescendo.

Bill was too fascinated to move and his cock hardened again. The effect of all these orgasms drove Alice to wakefulness, but not even the sight of Bill staring at her with his hard cock in his hand could keep her from attending to her needs. She continued to come over and over, louder and stronger.

Bill had thought his sister might be pissed at him and he'd be in trouble. He was just about to blurt out an abject apology when Alice surprised him.

Alice thought that she had been playing with herself while asleep and that her noises had brought her brother in to investigate. She was mortified and humiliated that her little step-brother had seen this and was worried that he might tell her Mom.

She wasn't worried about the masturbation, but she knew she would be in real trouble with her Mom for having shaped her cunt-fur. Her Mom would know that she was sexually active. Why else shave your bush? That could get her grounded for weeks. She begged Bill not to tell.

Bill was confused by this turn of events but pulled his pajama bottoms back on and returned to his room where he thought long and hard about what had happened. Having puzzled this all through he decided to take a chance the next night.

He figured that he had seen something that Alice wished to hide, although he wasn't sure what. But he figured he might take advantage. He entered Alice's room after she had gone to bed and told her he would tell their folks about how he had caught her playing with herself.

She begged him not to do so. He finally agreed not to tell in return for her giving him a hand job while she was naked and he was allowed to play with her tits.

She figured this the lesser of evils and agreed. She removed her nightgown displaying the wonderful tits that Bill wanted to play with. Bill stripped, presenting his already hard cock. Alice was impressed. It was bigger than her boyfriend's cock, the first and only one she'd ever sucked. anHerd her boyfriend, Fred, was an 18-year old football star. Her thirteen year old stepbrother was bigger, a good 5 inches she guessed.

She had sucked Fred and also given him hand jobs so she knew what to do. While Alice stroked Bill's cock, Bill caressed her magnificent boobs. The effect on Bill's cock and balls was electric. His cock got rock hard and the jizz in his balls boiled.

To her surprise Alice's nipples hardened under his ministrations and her cunt began to get wet. She was servicing Bill reluctantly, but she found herself turned on.

She had angled herself so as not to have Bill's jizz spatter her, but at the last minute Bill turned. When he fired, huge gobs of sticky, slimy jizz flew onto her tits.

She was amazed at the effect on her. The spots where the jizz had struck her immediately began to tingle and the feeling spread rapidly throughout her body. Within seconds she was out of control. Her wanton cunt was on fire and she could not keep herself from fingering herself frantically.

She came in a shuddering roar and then came again even louder. She gasped for breath, writhed and kept eagerly thrusting her fingers into her now sopping wet cunt. She gasped for air and turned purple from pleasure. For almost 15 minutes she came in paroxysm after paroxysm of the most fantastic pleasure she had ever felt.

Bill was astonished by his sister's reaction. He could not figure out what had had this effect on her. When she came back to earth she too was confused. All she knew is that she had had the most intense and pleasurable experience she had ever imagined and that it had begun when Bill's jizz slathered her tits.

Bill left, but for the rest of the night Alice's body continued to want service. The intensity of orgasm slowly decreased, but she had to masturbate herself over and over. She could not get enough.

She wondered if there was something in Bill's jizz that caused this effect. She had certainly never heard of such a thing. The next day she had recovered enough that she could concentrate on googling this effect but could find nothing. But she knew two things. It had been fantastic and it had started with Bill's jizz.

By the middle of the afternoon the effects of her high had worn off and she was beginning to slip into depression. She desperately wanted the feelings of the previous night and hoped that her theory was right.

Bill too had been thinking. Twice he had gotten his jizz on his stepsister and twice she had gone wild. Could he be so lucky that it was his jizz that caused this effect? If so the possibilities were wonderful to contemplate.

That night Bill and Alice had slightly different agendas but both were intent on getting jizz out of Bill's balls into Alice's voluptuous body. Alice wanted to give Bill another hand job, but Bill wanted more.