Jason Hodgson had just gotten home from school and was in his room checking his e-mail when the phone rang. It was his brother-in-law, Tony.
"Jason, you know that Lisa's birthday is in less than two weeks, don't you?" he asked.
"Ah, ya." Jason said, hoping Tony would believe his lie. Actually, it had slipped his mind.
"Well, I was thinking that I'd like to do something special for her, and I was wondering if you could babysit for us that night? I want to take her out to dinner, and maybe a movie, or some dancing at a club afterwards." Tony explained.
"Sure, Tony, that'll be no problem. Just remind me a few days before, okay." Jason said "I don't mind at all. I'd be happy to."
Jason had always gotten along well with his brother-in-law, and he was more than happy to be able to do this favour for them -- especially since it was his older sister's birthday. Jason had always been very fond of his older sister. But if the truth were told, his fondness extended beyond the usual feelings that most siblings have for one-another.
Lisa was a very pretty young woman, and despite the fact that she was his sister Jason took every opportunity he got to let his eyes roam over her curvy sexy body when she was around him. At 5'6" with shoulder length brown hair and piercing blue eyes, Lisa was just about the prettiest woman that Jason had ever seen. Often he found himself staring at her firm round butt as she walked by him, or sneaking a peek down her top when she would bend over in front of him. Often Jason wondered if his sister knew that he was lustfully oogling her, but as far as he knew, if she did she never let on. This year she was turning twenty-five, and Mark wanted to make her birthday special.
* * * * *
Four days before her birthday Lisa called Jason one evening to see if he had time the next day to babysit for her the following day.
"Mark said he's taking me out for my birthday and I'd like to buy a new dress to wear, and I was wondering if you could watch Brandon while I go out tomorrow for a while?" she asked her brother.
"Ahhh... I have classes in the morning until 11:30, but I can skip the afternoon. I only have one; it'll be no problem." Jason said.
"Are you sure?" his sister asked.
"Ya, it's okay. Besides, it's for your birthday. Now that you're getting old I should respect my elders." he said laughing.
"Old?!" Lisa said in mock anger "Twenty-five's not old! You wait -- in five years you'll be my age, and we'll see how you like being called old, little brother."
"I'll see you tomorrow around noon, sis." Jason said laughing as he rang off with Lisa.
Jason was really looking foreward to seeing his sister. Any time he got to spend alone with her was wonderful, and the next day he practically ran to his car in the university parking lot once his last classes were done, then quickly drove to her and Mark's house. He let himself in and found Lisa finishing up some dishes in the kitchen. She was wearing a pair of jeans which Jason noticed hugged her hips and round ass very nicely, and a simple t-shirt. As she turned around to greet her brother his eyes roamed up towards her breasts and he noticed her nipples poking out slightly through her t-shirt and he felt his cock twitch to life. Although Lisa's breasts weren't overly large, Jason always found them very nice. They were round and full, and on several occasions when she wasn't wearing a bra he noticed that they turned up slightly, and seemed to be very firm.
"Thanks so much for doing this, Jason. I shouldn't be too long -- maybe an hour or so." his sister said.
"That's no problem, sis. I don't have any plans, so take your time." he said smiling at her.
"Okay. Brandon's asleep upstairs so he should be ok. Just go check on him a couple of times, but other than that, make yourself at home." she said.
Jason nodded.
"Thanks again, Jason. You're a big help!" his sister said and gave him a quick hug and kissed his cheek.
Jason felt his sister's breasts brush over his arm and his cock began getting hard. He felt his face flush, and he suddenly felt quite nervous. Lisa immediately sensed his nervousness when she saw him blush and she clutched his arms and giggled.
"I'm going to get going. I'll see you later." Lisa said as she grabbed a coat and her purse.
Jason smiled at his sister, and stared at her as she walked to her car, wondering if she could tell he'd gotten turned-on around her.
"She sure looks great in those jeans." he thought to himself as he stared at his sister walking.
Once Lisa was gone Jason got some school books from his backpack and began working on some homework to pass the time until his sister returned. Once he'd finished with that he looked in their fridge to see what they had and made himself a sandwich then went to watch tv. A little over an hour later he heard the back door open and his sister calling out to him and he went out in the kitchen to meet her. Lisa was standing there carrying a large paper shopping bag with a big smile on her face.
"That didn't take you too long." he said.
"I can't believe my luck!" Lisa said setting the bag down on the kitchen table and taking her jacket off "They were having a sale, and I found this amazing dress at 30% off. I'm going to go try it on."
Jason watched his sister walk by him as she went up to her bedroom to change, then he returned to the living room to watch some more tv. A short while later he heard her calling out to him from upstairs.
"Come up here and see it, Jason, and tell me what you think." his sister said.
Jason put his glass of Pepsi down on the coffee table and went up to his sister's bedroom. When he walked in the room Jason was shocked by how sexy his sister looked in her new dress. It was black with a plunging neckline, and came down to just above Lisa's knees. She smiled at him and turned around to show him the dress. The back of the dress was open so Lisa's back was exposed and Jason felt himself getting hard as he watched his sister modelling for him. One thing he noticed was that the way the dress was designed meant that her bra strap was showing in back.
"So what do you think." Lisa said grinning.
"Wow, sis, you look great!" he said running his eyes over her, hoping she wouldn't notice the growing bulge in his jeans.
"Really?" she said surprised as she spun around once more.
"Ya... just one thing. Turn around." he said.
Lisa turned around and her brother took a few steps towards her and hooked his finger in her bra strap and snapped it.
"Something will have to be done about this." he said with a laugh.
Lisa reached in back and ran her fingers over the strap and smiled.
"Ya, I forgot about that. Hold on." she said laughing.
Jason watched as he sister turned so she had her back directly to him and slid the straps of her dress off her shoulders.
"No peeking at my boobs, little brother." she said with a giggle as she reached back to unhook her bra then let it slide down her arms onto the floor.
Lisa pulled the dress back up over herself then turned around to face her brother again. She looked down at her chest and smiled up at him as she adjusted it to make sure her breasts were fully covered.
"Better?" she said smiling as she turned around slowly.
"Ya." Jason said as he stared at his sister.
Lisa walked over to the mirror to look at herself. She ran her hands down over the dress, smoothing out a few wrinkles, then turned left and right to check herself out. She noticed that her nipples were hard and quite visible through the thin material and let out a laugh, feeling sexy and daring.
"What's so funny?" her brother asked.
Lisa turned around and walked over to her brother, and with both hands pointed to her nipples.
"These!" she said smirking "Looks like I'll be putting on a show if I get cold."
Jason blushed and quickly turned his head up from his sister's chest to her blue eyes, which had a peculiar look to them that Jason had never noticed before.
Lisa had been watching as her brother stared at her hard nipples through the dress and felt a surge of passion go through her body that ended up at her clit. She felt it jump and she got slightly wet. This was not the first time over the years that she had noticed Jason staring at her body. At first she used to find it sort of creepy that her little brother was looking at her like that, but she found him so shy and nervous around her at times like that too that she couldn't get upset with him. Eventually she began to find it cute, then in time she enjoyed teasing him. To her it was sexy fun because it was forbidden, and she liked to see how much she could tease him.
"What's the matter, Jason, never seen hard nipples before?" she teased.
