Dan grew up in a strict religious family. His parents had been married since they were 19 years old, and they started having children shortly thereafter. By the time they were 28, they had two sons and a daughter. Dan is in the middle. His brother, Mark, is three years older. His sister, Mary, is three years younger. Dan is 21 years old and doesn't quite fit into the family dynamic.
His family's lifestyle revolves almost completely around church. Mission trips, bible studies, prayer groups...the whole works. Mark and Mary pretty much fell in line with the expectations, but Dan had never felt any connection to the religion that had been shoved down his throat his whole life.
He was entering his third year of college and lived at home. His older brother moved out of the house after he finished college a year earlier, leaving Dan and his soon-to-be high school senior sister at home. Mark and Dan had always gotten along great, but Mark had fit into the straight-edge evangelical routine much more easily than Dan. Recently, they hadn't spent much time together. Mark's wife fit the mold his mom envisioned, and they were on their way to starting their own family.
Mary is a spitting image of their mom, both in personality and appearance. Just like her mom, Mary has a petite, athletic figure. She has sculpted legs and a shapely butt, probably from all the years of dance classes. She has 34C breasts. Dan only knew this because both she and her mom hung their bras on the drying rack in the laundry room regularly. He hadn't ever thought much of it until a few weeks ago when he went in to his parents room to ask his dad a question. His mom was coming out of their walk-in closet, completely unaware her son was in the room. He saw his mom wearing her white cotton underwear and nothing else. Dan apologized and turned away from his topless mom covering her boobs with her hands, but she hadn't covered up quickly enough. Her large, dark areolas and pointy nipples were engrained permanently in his memory.
Mary is a smart and capable young girl, but extremely sheltered and naive about the real world, at least from Dan's perspective. She is a good looking girl, and lately he couldn't help but imagine what her tits looked like. The one nice part about their parents house was the backyard pool. Mary had worn the same modest bikini for the last couple years, and it didn't show off nearly as much skin as Dan wanted it to.
One day when he was doing laundry, Dan found her bathing suit in the washer and had an idea. He ripped the strap that held it together, then hung it on the drying rack. She would have to get a new one now, and Dan hatched an idea to make sure it was one he liked. She turned 18 the week before, and he hadn't bought her anything other than a birthday card. He decided to go buy her a new swim suit. He told her about the ripped strap, and she was bummed out. She hadn't been babysitting much because of the pandemic, so she was completely broke. Dan sighed and told her he would help her out with a late birthday present. Her eyes shot wide open as she smiled at her big brother.
"You would really do that? They're like 50 bucks," she asked excitedly.
"I have some extra cash, and it's about time you ditch that boring old bathing suit anyways," Dan replied.
"Thanks! When should we go get it?" she asked.
"What do you mean we?" Dan asked playfully. "It's a present. Shouldn't I be the one to pick it out?"
"Um, I guess. Usually I try them on first, though," Mary said.
"They don't let you try things on with Covid going around," I told her. "If you hate it or it doesn't fit you can take it back."
"Okay, that works! Let's see if you have any taste," she joked as Dan grabbed his keys and left for the mall.
Dan was excited as he shuffled through the racks looking for one that he liked. He wasn't familiar with sizing of women's clothing, but he had an idea of at least her bust measurement. He didn't want to take a chance guessing, though, so he decided to text and ask her what size she wears.
"What size you wear sis?" he texted her.
"The ripped one is a small, so that should work," came the reply.
"You bought that like three years ago, though. Not to sound weird, but you've kinda grown up a bit since then," Dan replied. "It says to get a small for A or B cups. Is that gonna work?"
Dan knew she was a C cup, but texting his innocent little sister about her breasts was turning him on.
"I'm a 34 C. Maybe I need medium," came her reply.
"Thanks, sis," Dan said as a purple halter top and matching string bikini set caught his attention.
It was a light purple with frilly trim. The top was cut to accentuate cleavage while still covering a respectable amount of skin. It was held up by a string around the back of the neck and a tie around the back. The bottoms matched the color and style of the top. The string together style allowed for enough coverage to not seem weird, but the bikini cut would show off her ass more than anything she'd worn before. It would sit low on her hips and the crotch was cut much more narrowly than her old suit. There wasn't much of a liner, and it seemed almost like a mix betweenas bathing suit and underwear. This was the one. Dan checked the price tag, and it was $39.99, but it had a red sticker on the label. The sign above the racks of bikinis indicated "all swimwear and intimate wear with red sticker buy one get one equal or lesser value free."
Dan's face turned a little red as he processed what that meant for him in this moment. He was already turned on buying the swimsuit, and now he was going to push it even further, all under the guise of taking advantage of the sale. He wandered over to a display of lingerie. After a few minutes he found a white lace bra and panties set that left little to the imagination. The lacey fabric left small gaps in the pattern, making it partially transparent. He pictured seeing Mary's nipples peaking through the lingerie, even though she never walked around in her underwear. He found her size and went to the checkout. The woman behind the counter smiled and told Dan his lucky lady would be happy with his choices. He felt his dick move in his pants, and nearly told the woman he was buying his sister a birthday gift before changing his mind.
"There was a sale on swimwear, so I grabbed some undies for free for you," he texted Mary.
"Lol. I have enough underwear, Dan."
"Those old worn out cotton briefs I always see in the hamper? I think you could use a bit of an upgrade, girl!"
"They are kind of old, I guess," she said.
"I'll be home soon. Are you busy? I wanna make sure everything fits, or else I can return them," Dan texted her.
"I'm just reading a book in my room," she replied.
Ten minutes later Dan walked in the front door. The house was silent. His mom and dad were at our pastor's lake home for a weekend of married couples' bible study with a group of other couples from church. He walked up the stairs and knocked on Mary's door before opening it and walking in. She was lying on her belly with her elbows propping her up as she read. She closed her book and sat up as Dan entered, eager to try on her new suit. Dan set the bag down on her bed and she pulled the bikini out first.
"Wow, this is cute," she said. "Not sure if I can pull something like this off, though."
"Sure you can," he told her.
"I'll try it on, but it's a lot smaller than what I'm used to," she replied.
"Okay, I'll step outside while you change. Let me know when I can come back in," he said.
He waited outside her door for about five minutes, and was starting to wonder what was taking so long when she cracked the door open and told him it was too small for her. Dan gently pushed the door open and slid past her and sat on her bed.
"Fashion show time!" he said. "It doesn't seem too small. Give me a little twirl."
She was blushing as she looked at him nervously. "I don't think I can wear this. Don't you think it's too skimpy?"
She spun around, giving Dan a good look at her wearing the purple bikini. It molded to her form perfectly. He had never seen this much skin on her, but it didn't seem slutty or anything. It just made her look really hot. Her breasts were held up perfectly by the top, and he thought he could see a faint outline of her nipples. The bottom covered a decent amount of her butt, but seemed to be held relatively loosely in place. The front was snug, but didn't show any camel toe. Dan wondered if she had a bush or if she trimmed down there. He adjusted himself to make sure his hardening dick wouldn't make a tent in his pants. Dan playfully whistled at Mary.
"You look great, sis! It fits perfectly," he said.
"Are you sure I don't look stupid? I feel like I'm half naked," she said.
"That's how it's supposed to be," he came back chuckling. "Have you seen my swim suit? My shorts only go halfway down my thigh, and I don't even have a top!"
"Haha okay, I guess you're right," she told him.
"Perfect. I hope you like the underwear I picked out, too," he said walking to the door. "Do you want to go swimming soon?"
"Yeah, I'll meet you out there in ten minutes," she said. "I'm gonna try the undies on quick first."
Dan went back to his room and took his clothes off and lay back on his bed. He pictured his sister trying on the lacy lingerie he bought her and he was rock hard. He couldn't wear his tight swim trunks with a hard on, so he tugged himself thinking about Mary. He cleaned off with the boxers he had been wearing then found his trunks, put them on and went outside to the pool. He lay down on one of the lounge chairs reclined all the way back and put sunglasses on. After just a couple minutes under the hot sun the patio door slid open and Mary came outside. She walked over and laid her towel on the lounger next to Dan. He pulled his sunglasses off his face and looked up at her. She had some pretty distinct tan lines where her old suit had covered her skin.
"You should put some sunscreen on," he told her.
"I already did, but can you help me with my back?" she asked. "I'm pretty sure I missed a spot or two."
Dan told her to lie down on the lounger and stood up as she handed him a bottle of sunscreen. When she lay down he straddled the back of her thighs and sat on top of her. He rubbed the lotion thoroughly into her back, careful to not miss anywhere. Right before he stood up he noticed a strip of pale skin at the top of her legs and onto the part of her butt the suit left uncovered. He slid back, squirted some lotion in his palms and rubbed it into the skin beneath the bottom cut of her suit. She turned her head back surprised.
"Doesn't look like you got any down here," Dan said calmly while his fingers touched the hem of her bikini as he finished rubbing the sunscreen on her butt cheeks.
