***Earlier that night***
"You must be Josh," Abby said, "Tara told me you were coming. My name is Abby. Sorry about my appearance, I just got out of the pool. Tara is waiting on the back porch for you, it's right through the kitchen."
She pointed Josh in the right direction and headed upstairs. She smiled to herself as she thought about how this all began.
Every so often she would sneak into Tara's room while she was away and read her diary. Tara would put everything from what she did at school to what she did with the boys she was dating. Tara had been sleeping with all of the boys she had dated for the last six months. Abby liked to read about these encounters and imagine herself in her sister's place as she masturbated. Two weeks ago though she found something especially interesting.
On this particular trip into Tara's diary, Abby found more than a past experience. As she flipped through the more recent entries, she realized that Tara was planning something for the future, probably the near future. While she couldn't find a date or time, she saw exactly what Tara wanted to do and that she wanted to do it with a guy named Josh. Abby was still a virgin, albeit a very curious virgin. She hadn't had any experience with sex past masturbating and had no real knowledge other than what they taught in sex ed and things she saw on the internet. She decided that is she planned it right, she might be able to use her sisters scheme as a chance to see some of the things she had only read about live and in person. Her pussy began to leak as she began to think of the possibilities and read through Tara's plan.
The diary said that she wanted to start at the pool and spend the weekend having sex in various places both inside and outside the house. Tara obviously was going to need to wait for their parents to leave for the weekend, which meant Abby would have a little warning as to when this was going to happen. Abby also knew that she would also need to be gone for the weekend, and she would have to find her way back into the house without her sister noticing.
She didn't have long to plan before the pieces fell into place for Tara. As luck would have it, two days later the girls parents announced they were planning on going on a weekend trip to the family cabin to open it up for the season. They would be leaving in two weeks. Abby knew she needed to scramble to make sure she was there, but not there for that weekend.
The next day at school, Abby talked to her best friend Jen when they got a moment in private. Jen was about 5 ft 4 in with long blond hair and blue eyes. She wasn't thin, but wasn't fat either. She had large breasts which did a good job of directing attention away from her slightly chubby stomach. The important part was she had her own car and would be able to provide Abby with both the excuse to get away from the house as well as the means to get back.
"Hey Jen, I need a huge favor." Abby said.
"What's up?" Jen asked.
Abby explained to Jen what was going on with her sister and Josh.
"I really want to spy on them." Abby said.
"I will help you on one condition; you have to let me go with you." Jen said.
Abby hadn't thought about this, and it made her plans much more complicated. After a couple moments though she realized that there was no way to make this work with Jen and reluctantly agreed. They made plans for Abby to pretend to she was staying at Jen's for the weekend and for Jen to pick her up Friday night around 8:30. They then worked together to figure out how to get back into position to watch Tara and Josh. It wasn't long before they had a plan that they felt confident would work.
A couple days later Abby told her parents at dinner that she would be going to Jen's next weekend for the entire weekend. Tara visibly perked up and Abby couldn't help but smile to herself.
Things were uneventful for next week. Abby continued to check Tara's diary to see any indication of when Josh would be arriving and that she was actually going through with her plan. However, she never saw any mention of it. She was starting to worry that she was mistaken about Tara's plans or that Tara had changed her mind. What if she was just imagining possible plans? What if Tara didn't actually intend to follow through? Luckily, on the Friday that there parents were leaving, Tara came to Abby after school.
"Hey Abby, I have a friend coming over around 8." Tara said.
"Oh?" asked Abby in her best uninterested voice. "Who's coming over?"
"A guy named Josh from school is coming over to give me some help in Math." Tara said.
"Ahh, cool. Well Jen will be over to pick me up around 8:30." Abby said.
"Ok, well I'm going to take a shower and change, then I'm going to relax out by the pool. When the door bell rings could you answer it and point Josh out to me?" Tara asked.
"Sure." Abby responded.
Tara left and Abby found she suddenly had butterflies in her stomach, as well as a growing warmth between her legs. This was actually going to happen! She went to her room and sat on her bed, waiting for Tara to finish her shower. When she heard Tara get out of the shower, leave their shared bathroom, and head down to the pool, she quickly stripped down to her underwear and put on a robe. Then she headed to the shower and soaked her hair so that it looked like she had been swimming.