** This is a work of fiction based on a few real events. Everyone in this story is over 18. And it's not to be taken seriously. This contains elements of small penis humiliation, incest, voyeurism, light bdsm, and other fetishes. If that's not something you usually like, then you won't like this story. As always feedback is both helpful and appreciated, I am not a professional writer and I am always learning. **
Growing up with sisters you learn to deal with certain things as a boy. As the most shared space and the one where the most private matters occur, the bathroom creates a significant arena of tension among siblings.
You learn to live with hair all over the place, with products crowding the sink. And what seemed like an ever-growing assortment of shampoos, conditioners, and cleansers in the shower. Here's what I know, girls use a lot of products for their hair, for their skin, and their teeth, and for some reason, both of my sisters had to have their own products for everything. Why they couldn't share shampoo and conditioner is an unknown mystery with the answer, "because our hair is different." They're sisters, how different can their hair be?
It was fine when we were little, but as we got older the problem became increasingly worse, with tampons and pads, and bras and panties all over the bathroom. And what once was considered acceptable became "immodest." I used to be able to go pee while they were in the shower, but now I had to go downstairs and use the half bath, I know #firstworldproblems, but still, it sucked I couldn't just use the bathroom attached to my room.
The situation got better when my oldest sister, Shelby, went off to college. My younger sister, Kat (short for Katie), and I still got into fights, but it wasn't nearly as bad as before. The real problem started the Christmas after Kat turned 18, and we were all home for winter break.
"Kat!" I banged on the bathroom door. Shelby and Kat shared a room and we had a Jack and Jill bathroom that separated our rooms. I knew it was Kat in there because I could hear her singing in the shower.
"Can you please just unlock the door so I can pee?"
"Go downstairs!" She called out. The problem wasn't just going downstairs, like most healthy 19-year-old boys in the morning, I had a raging hard-on, and making my way down to the other bathroom with a boner and possibly being seen by my mom wasn't an ideal situation. Both of our parents work a lot, mom is the head of nursing at her hospital so she gets to set the schedules but still works long hours most days.
"I am coming in, I promise I won't look!" I knew she'd be pissed off, but I grabbed the little key from above the door and made my way inside. The way our bathroom was set up there was a double vanity against the outside wall, the shower/tub combo was against my bedroom wall, a door going to the hallway on the inside wall and then the toilet was against Shelby and Kat's room. In newer homes, I've seen the toilet is usually enclosed in a water closet, but not in ours, just a half-wall separating the toilet from the vanity area. Our bedrooms were big, Kat and Shelby both had full-size beds, while I just had a twin, but I also had a computer desk, couch, and TV for my game system.
"What the hell!" She cried out.
"I am sorry I had to pee, just stay in the shower." Even though I had to pee badly, it still took a few seconds to wait for my erection to relax enough to go.
"What are you doing!" She pouted. I was finally able to let my stream flow, a chill shot through me, and I shook. Relieved, I flushed the toilet and turned around.
"Jesus!" I snorted, standing right in front of me was my wet and naked sister. Our mom must've changed out the shower curtain to a clear one. "I am so sorry. I didn't know!"
Dylan!" Kat yelled, snapping me out of my ogling.
I stammered and rushed out of the room. But that one single moment would change everything for us.
Safely, in my room I couldn't believe what I had seen. I knew Kat had large breasts, you'd have to have the willpower of a monk to not occasionally glance down at them especially when she wore one of her tight tops or swimsuit. Kat's the shorter and thicker of my sisters, maybe 5 feet tall, naturally wavy dark hair with unnatural blond highlights, and now at 18 years old, she was fucking hot.
Occasionally we would make bets and deals with each other, Kat would always bargain for someone to do her laundry, back over the summer I lost a bet and was washing her clothes when I took a peek at the size of one of her new bras, 34-DD.
Shelby, on the other hand, was just a bit shorter than me, probably 5'7, slim build, almost a pure black hair with the same wave to it that Kat has. She's a cute girl, with a prominent jawline, long neck, and defined cheekbones. She's finishing up her Master's degree but still has strong legs and a tight butt from playing volleyball all through high school and she still stays physically active. I've never been curious about her breasts enough to look at her bra, but I can't imagine she's more than a 32-B.
But right then, at that moment all I could do was think about Kat's large, perfectly shaped breasts, with her wet dark tits. Her areolas alone had to have been as big around as a baseball.
"Damn that curtain was like glass, she had to have seen me staring right at her tits." I thought. "Shit! my cock ached to be touched." I looked down and my slick basketball shorts were tenting showing off my modest size. I laid down on my bed on top of my covers and covered my face with my pillow. I was embarrassed for Kat, but even more embarrassed I was so hard for my sister. My heart was beating fast and flooding my ears with every thump.
"Dylan! What did you do?" The angry voice bellowed over me. Startled I threw the pillow at Shelby who was just a few feet away. She stood powerfully with her hands on her hips and anger on her face.
"SHIT, look!" Kat snapped pointing at my crotch. "Did I make you hard?" Kat was just behind Shelby wearing light blue panties and a pink sports bra that clung tightly to her still tacky skin.
"God, Kat, I am so sorry I had no idea that mom changed the shower curtain, I promise I thought it was still that old blue one!" I babbled and tried to cover my erection with the covers on the bed.
"I told you not to come in!"
"Why didn't you just use the bathroom downstairs?" Shelby fumed.
"I am sorry, I couldn't?"
"You must not have had to go THAT, bad it took you several seconds to start peeing once you... you... got it out." Kat accused.
"I... well... I had a problem, I couldn't go downstairs." I blushed.
"Oh, god!" Shelby cussed.
"What, I don't get it?" Kat asked.
"He had morning wood, Kat... an erection," Shelby stated.
"Then why was it still hard when we came in?" Kat asked, but I was fairly certain she already knew and just wanted to embarrass me.
"I...well... it came back."
"From something you saw?" Kat smiled, now I knew she was just playing with me and she seemed to enjoy it.
"Either way, it was wrong for you to open a locked bathroom door." Shelby scolded.
"I know, I am sorry."
"I am not sure that's good enough," Kat added. "I mean, it's not fair, now anytime you want you can just close your eyes and imagine my big wet titties." She said tracing her breasts, in her tight top.
"No, it's not enough." Shelby agreed.
"What can I do? I could do your laundry for a week?" That always seemed to work when we were younger, and honestly, I liked touching her bras and panties.
"Not the same?" Kat pursed her lips, crossed her arms, and tilted her head. "I think you deserve a smack to the balls."
"No Way!"
"Not like a kick of punch, just a swift slap," Kat demonstrated slapping her wrist.
"That sounds fair," Shelby joined in, "that should take the wind out of your sails."