Trudy lived in a nice middle class neighborhood with her brother, Tommy. He was one year older than her and had seen Trudy in various stages on undress many times. Often, he would masturbate as he stood next to her bed and watched her as she slept. Trudy would often sleep in just her panties, providing Tommy frequent opportunities to see her budding beauty.
Finally, it happened that Trudy woke up while Tommy was masturbating next to her bed. After the initial shock of seeing her brother whacking off next to her, she invited him into her bed. They made love for the first time that night. Lying next to each other, they promised to keep this newfound pleasure a secret between them.
In the next few afternoons, Trudy and Tommy spent plenty of time in bed together. They experimented, learning different ways to please themselves and each other. Sometimes they fucked hard, and sometimes they fucked tenderly. But always they fucked with one ear open, ever alert for their mother.
As they grew more comfortable with their newfound sexuality, Trudy relaxed enough to confide in her brother her excitement when it came to watching other people fuck. Tommy was thrilled, and relieved that Trudy did not hold his voyeuristic tendencies against him. So, each pleased that the other enjoyed watching, they decided to go out together one night and see what sexy scenes they could discover in their neighborhood.
They devised a plan where Tommy would tell their mother that he had to go over to a friend's house one evening to work on a school project. That same evening, Trudy agreed to leave her piano lessons a bit early, telling her teacher she had to get home to help her mother. The plan went off without a hitch and the two met just as it was getting dark in an alley not far from their house.
"We'll try the house on Pine Lane first," Tommy suggested, leading his sister down the back passageway.
"They like to have a quick evening fuck once in a while."
"You mean you've watched them before?" Trudy asked, trying to walk quietly.
"Sure! Did you think that I just started, like you?"
"Well, no," Trudy replied. "But I didn't know you knew so much about what other people do."
"I don't really know much at all," Tommy laughed. "I just know who likes to fuck. And when, and who doesn't close their curtains. Now come on!"
They hurried down one block, and up the next. Ahead of her, Trudy could see one brightly lit window and she felt her stomach tighten when she realized it was their goal. Tommy's hunch had been right. There were people in that room!
"What'd I tell you?" Tommy giggled. "Those people can't keep their hands off each other!"
Brother and sister moved around the trashcans across the alley from the back bedroom window, covering themselves as best they could. Arriving, they crouched down and Trudy's eyes went wide when she got her first good look at two people actually fucking.
"I can't believe it," she sighed. "Look at them go! How can she take it?"
"I don't know," Tommy mumbled. "But I know I can't. Feel this!"
He took her hand and guided it to the front of his pants. Without taking her eyes off the hot sight in front of her, Trudy felt his erection pounding against the fly of his jeans. She gave it a casual little squeeze and then let it go. Watching other people fucking was such a tremendous new experience, it took all of her concentration.
Inside the sparsely furnished bedroom, an older man and a young girl were both naked on the bed. The girl, her face turned slightly away from Trudy and Tommy, was on her hands and knees and the man was taking her from behind with long, powerful strokes. The short dark curls on the girl's head bounced when he rammed his cock into her, but she seemed to enjoy it. She held her body tightly and absorbed his pounding by slamming her ass back at him each time he filled her with his cock.
As if from a distance, Trudy heard her brother slide his zipper down. Then she sensed as much as heard him start to stroke his rigid prick. Trudy was getting plenty hot herself. The idea of spying on other people while they fucked had excited her but not nearly as much as actually doing it did. She could feel her cunt getting all soft and squishy and she shifted around, rubbing herself against the crotch of her panties.
"Turns you on, huh?" Tommy whispered, his hands moving on his cock while he grinned at his obviously excited sister.
"Yeah," Trudy's voice cracked. "Even more than I thought it would."
Tommy chuckled, a low and dirty sound. "You getting wet?" he asked.
Trudy didn't have to answer because her brother reached over and cupped the crotch of her panties under her short skirt. Trudy knew her cunt was very juicy and from the way her brother sighed, she knew too that her juices had soaked the crotch of her panties.
"Running like a river," Tommy sighed, massaging her wet crotch and feeling it become even wetter.
In her crouched position, Trudy opened up her thighs and balanced herself on just her tiptoes. With one hand, she held onto a nearby trashcan to keep from falling. She pushed her pussy back against her brothers' groping hand and began to pant, his fingers thrilling her through the silky covering of her panties . "Wait a minute," she finally sighed, pulling away from Tommy.
