Tom watched his sister Judy swim the length of the pool and climb the steps. Water dripped from her as she bent over to pick up the towel she had left on the lawn chair. He liked how her thin body looked and the way her breasts filled her bathing suit top. It covered enough to be almost modest yet still showed the tops of her flesh mounds and was tight enough to press them together forming a deep valley in the middle. Letting his eyes move lower he gazed intently at her buttocks. The separate bottom half of her suit fit just as snugly as the top letting him see her firmly rounded cheeks. While they were twins they weren't exact twins. It just happened they were born minutes apart.

"Hi, Sis," he tried to sound casual as he strode quickly to the edge and jumped into the water. He really didn't want her to see the lump forming in the front of his suit.

"Hi back, Todd. Been keeping an eye on me again?" she asked mockingly.

"Aw come on Judy. You're my sister, so why would I want to look at you?"

"Yeah right," she scoffed. "And I suppose that's a hot dog in your suit. What you see," she said giving him a good look, "is all you're going to see. Later dude." She walked into the house and to her room. Once there she peeked out the window at her bother. Her room faced the backyard and she had for a long time enjoyed watching him in the pool. He was thin but when he sported a lump like what he was now she became entranced and a bit aroused. Each time she saw him like that she would have to take care of herself using her fingers and each time she would come closer and closer to changing her mind. She was, after all, a very curious young woman.

Saturday morning and it promised to be hot all day. Tom was being lazy in the pool and it was only nine in the morning when Judy came out wearing her two piece suit that she knew he liked. She made a big show of laying out her towel and paraded around the pool teasing him with her body. Before long Tom decided it was time to get out.

"Think I'll take a shower and get the chlorine off me," he announced quickly turning his back and walking to the house. Again she had caused his young organ to grow into a large lump in his suit.

Judy smiled to herself. She knew that would happen just as she had figured. What Tom didn't know was just how much she had planned it. They were alone, their parents working. Today was their birthday. She waited long enough to be sure he was out of the shower before creeping silently in the house and down the hall. The door to his room wasn't quite closed leaving just enough of a gap for her to see inside. Judy saw her brother standing in front of his dresser his fingers wrapped firmly around his fully erect penis. He was watching himself in the mirror and she could see the intent look on his face. Just below his erection she saw his sack and was amazed at how big it was. Her mind was now made up and she went to her room and removed her bathing suit.

"Happy birthday Tom," she said slipping into his room with only a towel covering her body. She almost laughed at the shocked look on his face when she caught him playing with himself. "I thought you might like your present now before the folks get home." With that she dropped the towel and let him see her completely naked body.

Tom gasped when she came in and gasped again as he looked at her nakedness. It was a dream coming true, he thought still gripping his erect organ. She came closer and for the first time he noticed how her breasts bounce just a little with each step. He couldn't move or say anything as he watched her slowly get down on her knees in front of him. She carefully removed his hand and replaced it with her own, tightly clutching his throbbing organ and gently cupping his large sack.

"I've been wanting to try this for a long time," she said gazing intently at his rock hard erection. "The girls at school have talked about being with their boyfriends and how they like them to do certain things to them. Now I want to try it with you."

Her fingers tightened around his hot hard shaft and slowly she moved her hand up and down the length. It wasn't real thick but it was long and it felt very hot and hard. She could feel the ridges under the skin and how hard the flared purple skin was at the tip. After a few minutes of slowly stroking him she saw a drop of clear liquid oozing from the tight slit. Judy was curious about what the other girls had told her. She moved her head closer and lapped up the single drop with her tongue. It was salty and bitter yet very arousing as she poked the slit and tasted more. Without even thinking as her hand moved down exposing most of his shaft she opened her mouth and put the head inside. Her lips gripped it firmly and she moved to take more inside until her lips touched her tightly clamped hand. It was marvelous and she wanted more. Over and over she moved her head up and down loving the feel of his hot shaft and how it throbbed. The skin was smooth like silk and a few more drops oozed onto her tongue. Tom felt a new sensation as she swallowed and he moaned.

Judy experimented to see just how much of him she could take and removed her hand. She was surprised to find she could take most of him before gagging and pulling back. Her fingers went around his shaft at the point where she could more rapidly bob her head without choking. She knew she had to stop to keep him from climaxing to soon. Judy wanted this to last longer than a few minutes and pulled back.

"I can't believe how something so hard can feel so soft," she said looking at him.

"I can't believe I'm seeing this," Tom replied. "How about letting me feel you?"

Judy got up and sat at the foot of his bed. He knelt down opening her legs. Her sex was sparsely covered and he could easily see the pink between the folds. He gently touched her naked breasts and felt her nipples grow instantly hard poking into his palms. Tom carefully gave them a squeeze as was rewarded by her soft moaning. He grew more bold and took her nipples in his fingers pinching lightly. Judy moaned more and pressed her chest to his hands.

Now it was his turn to experiment with what he had heard from other boys. He gently pushed and lay her on her back. Judy moved up and lay fully on the bed as she watched her bother kneel between her legs. She gasped when his tongue first touched her sensitive clit. He licked and lapped at it before slipping down and plunging it inside. His hands were firmly placed on her breasts and beginning to squeeze them harder. It felt good as her breathing started coming faster. She began thrashing her head from side to side as her climax quickly approached. Suddenly she was there gushing her orgasm onto his tongue. She gripped his head with her hands pulling him harder to her flowing sex.

"Now it's my turn," she said when her orgasm ended. She had him stand at the foot of the bed and got on her knees. Quickly she engulfed his throbbing shaft deeply in her wet mouth. Again and again she bobbed her head taking as much of his as she could.

"Wow, oh wow," Tom gasped watching her sucking him. "Yeah, faster," he moaned. "Shit now, I'm going to cum now."

Expecting her to pull back he was very surprised when she didn't. Instead her lips clamped even tighter as her free hand gently squeezed his large heavy full sack. Judy felt his erection growing harder and longer as she quickly released his sack and began fingering herself. She was determined to take all of him and taste his seed. The first huge gush nearly choked her as it filled her mouth. Knowing there would be more she quickly swallowed just in time as the next thick jet of his cream again filled her mouth. Over and over she swallowed as he continued to shoot his load. Just before the last of his cream filled her mouth she climaxed and plunged down his shaft with her head. Now all of his organ was inside entering her throat. Judy had to swallow just to keep from gagging and the sensation her throat muscles made on the head of his organ caused Tom to suddenly renew his orgasm. Fresh gobs of his hot cream erupted and flowed down her throat into her waiting belly. Judy was surprised and pleased at the same time. She found she was able to really take all of him and bobbed her head along his entire shaft. His orgasm finally ended and she could feel him beginning to shrink down. When releasing him she saw his organ becoming smaller and she licked her wet fingers clean of her own recent climax.

"I never would have believed this would happen," Tom said slightly out of breath.

"You and me both," Judy replied. "But now that is has I like it. How long before you can do it again?" she asked.

"Usually not until the next day but now I don't know. It could be just a couple of hours. Of course I don't think I could give as much so soon."

"That's alright," she said calmly. "I guess I can wait."

"Doesn't mean I can't do you again," he said excitedly. "I hear girls can do it lots more times and sooner than boys."

"Back off sport. Don't think just because we did this you can start taking advantage of me. I'll decided when and where we do it again, clear?"

"Yeah, but I ain't gonna like it." His face dropped but brightened when she laughed. He suddenly knew it wouldn't be very long until the next time.

A week went by and the twins kept their distance. Not there was anything wrong or regrets but more to keep their parents off guard. It wasn't easy for either of them to keep away and even harder to keep up the routine of sibling rivalry, but they managed to make it look good. Friday night came and their parents went to a party secure in the knowledge that their children would be home fighting as they always did. Even the television was grounds for an argument, but they had grown accustomed to it.

Fifteen minutes after they were alone Judy flopped herself down beside her bother on the sofa. He was watching some war movie and paid her little attention other than grumping when she leaned against him. He quickly changed his mind when her hand began rubbing the front of his pants. He hadn't even looked at her until her rubbing began to arouse him, then he looked at her. Her blouse was thin and half unbuttoned letting him see a lot of her breasts. He could see her nipples were hard as the poked at the material. Forgetting the movie he relaxed and let her have her way. She opened his pants and pulled down the zipper. Gently reaching inside Judy pulled out his rapidly growing erection wrapping her fingers around his not quite hard shaft.