Step-Sisters Secret - One Shot (Patreon)

*As the title suggests, this story contains a (very) sexual step-siblings fantasy dynamic. If that's not for you, well....what's wrong with you*

With the semester pretty much over and only final exams left, you were at home a lot more and finally able to sleep in. You were still adjusting to your new house, it had only been a month since you moved in with your dad and new step-mom and step-sister, so things were still a bit fresh. After 18 years of living with just you and your dad, having two more people in the house was the strangest part, but you were adjusting. 

You liked your step-mom. She was a hard worker, very respectful to you and your dad clearly was head over heels for her. Cassidy, your new step-sister, was a different story. You hadn’t really spent that much time with her before moving into the house, so there was a weird distance between the two of you that you weren’t sure would get resolved. It didn’t help that she was a year older than you and was your high-school crush for the two long years you were both in school together. 

She was just as gorgeous as she was then too; blonde, petite but curvy. Big perky breasts and a tone ass that she worked on daily. This made things all the more awkward. You couldn’t help but be attracted to her, she was your literal dream girl, and now she's walking around your house in booty shorts and a tank-top with no bra. It made studying for your finals hard when you were horny from her all the time. 

This morning though, everything changed. You rolled out of your bed and put some clothes on before going to your bedroom door. When you swung it open, you saw Cassidy, standing there in the hallway with her bed sheets in hand. She froze when she saw you, eyes wide and panicked. It took you a second to figure out what was going on but when you did, your eyes widened too. 

Cassidy had wet the bed. Her sheets were soaked and her booty shorts were too.

After about ten seconds of stunned silent stillness, Cassidy whipped around and ran into her room, closing the door behind her. You remained where you were, still shocked about what you’d just seen. Finally you shrugged and went into the kitchen. Both your dad and step-mom were out at work so it was just you and Cassidy alone until 5:30pm. 

You got a bowl out for some cereal and when you were pouring the milk in, Cassidy came slowly out of her room with her head down. She got to the opposite edge of the kitchen, now sporting a new pair of pj bottoms, before softly speaking. 

“Hey…” she said awkwardly. 

“Hey…” you said with a soft chuckle. There was a long pause, you ate some cereal. 

“So...about what you just saw…” She started to raise her head.

“What about it?”

“Well….” She ran over to you in a surprise burst of speed and grabbed your spoon arm. “I wet the bed. Fuck, I’ve never told anyone that” She confessed loudly. You couldn’t help but laugh again.

“Yeah I could see that!” 

“You don’t understand, nobody knows” she gripped your arm desperately.

“I mean...if I wet the bed I wouldn’t go spreading that news to everyone either”

“No you don’t understand, not even my mom knows.”

‘Ah, so that’s why she’s so stressed’ you thought, ‘she doesn’t want her mom to know.’

“Why haven’t you told her? This is like a medical issue or something…” You say.

“You don’t understand,” she said, finally letting go of your arm, “ i used to wet the bed a lot, and for a while I thought I was done with it. But when I was 14 I wet the bed once, and my mom put me in diapers for the whole rest of the year!” 

You almost laughed at her embarrassment, but restrained yourself. “Isn’t that good? To be protected?” you asked. 

“Ugh. It's embarrassing. I couldn’t go to sleepovers because she would tell the other parent to check I was wearing them before I went to bed, and on long car trips she would make me wear them the whole time in case I fell asleep in the car. She is such a psycho about it!” 

“She sounds tough, but how often do you wet the bed now?” She blushed when you asked, and hung her head again. You decided to answer your own question. “Every night now?”

She ran back and held your arm again. He tits jumped around and you caught a glimpse of a nipple escaping the tank top. Your cock got the message immediately. 

“Only for a few months, I think it's stress or something I don't know. I’ve been able to get away with it so far because mom always works early and I usually don't work until the afternoon so I can wash the sheets before she gets back. The only thing I’m grateful for is that she still doesn’t trust me and I’ve had a plastic mattress protector on my bed for as long as I can remember.”

Your eyes couldn’t help but take another glance down at her tit which had now fully escaped the tank top. You had to move your hand down to cover your cock which was growing hard rapidly. 

“I don’t know, I know it’s embarrassing but shouldn’t you tell her? Or at least get some protection for yourself?”

“No. I couldn’t, she would know. I have a feeling she already knows just based on how much detergent is being used. But you can't tell her please please please you can’t I’ll do anything!”

‘Anything?’ your horny mind already had thoughts and you glanced down at her exposed breast again. 

“Anything” you said. You couldn’t believe it came out but it did, and with such confidence too.

“Yes anything, I’ll do…” She stopped as you moved the hand hiding your cock. It pitched a tent so high in your pj’s that her eyes widened.  

“Anything?” You asked again. She bit her lip and contemplated. Slowly she reached over and grabbed it over your pants. She was stunned by the size of it, and she took a deep breath. 

“Okay…” she whispered, “but I have to pee first-”

“No. Now.” You demanded, grabbing her wrist that was on your cock. She stares at you, half horny and half afraid, before grabbing at your waistband and tugging your pj’s down. Slowly she kneeled, eye’s locked with yours, before pressing her luscious full lips against your cock. You moan as she starts to suck, twist, and stroke your cock. Slowly at first, then faster and deeper. She had no gag reflex, and her lips were so plump they were practically made for sucking cock. Suddenly she stopped. 

“Please, I can’t hold it, I need to go now!” she begged, still stroking your cock.

“Then go” you offer, but she doesn’t get it at first. She tries to get up but you push her back down. With a confused look, she gazes up at you wanting to ask why, to which you say: “Go.”

She breaks eye contact, knowing finally what you mean, and starts sucking again. After a few seconds you hear it, a hissing of piss on fabric and the trickling of liquid hitting the ground. It was like the act of degradation just turned her on more, as she sucked harder and faster as she pushed more piss out into her pj’s. You felt the warm puddle form under your feet and came instantly. 

Cassidy slowed, sucking every last drop of cum from your dick, before standing up, inches away from you still. 

“Well, looks like someone made another mess,” you said to her, “I think it’s time we get some protection for you.”