You do not.

You decline the challenge and finish shopping. Once home, your Dad and brother help you bring in the groceries. Afterwards you go to take a shower. Your phone chimes with a new challenge.

"Don't lock the door = $100

Leave the door ajar = $250"

Reading the rules, it seems you must choose before getting undressed. You leave the door ajar and start stripping your clothes off. You get down to just your panties when your brother walks in. You stare at him in semi real shock but he doesn't miss a beat.

"Sup Tits-mcGee?" He says as he flicks your nipples. "Forget to close the door?"

"Jason, get out." You say as you cover your nipples with your hands.

Your breasts spill out around your hands with just your now erect nipples covered. He pulls his pants down and sits on the toilet. You turn away from him, facing the shower.

"Why? You got something to hide? Is it here?" He asks before tugging your panties down.

"JASON!" You shout as you stumble backwards with your panties around your knees.

You fall in his lap. You feel his flaccid cock against your bare pussy.

"Whoa Jen, I am not a chair." He says mockingly.

"You two better not be fighting!" Your dad yells as he approaches the bathroom.

You quickly get off your brother's lap and hide in the shower. Your dad knocks at the door.

"What's the problem?" He asks.

"Nothing Dad, Jennifer and I were just trying to figure out who gets to shower first." Jason answers.

"Is that true Jennifer?" He asks into the bathroom.

"Y-yes dad, but we worked it out." You say.

"Okay, good, no more fighting or you are gonna have to start paying rent." You dad says, walking away.

Jason stand up, flushes, strips his clothes off and steps into the shower with you.

"Jason? What the fuck?" You whisper yell at him.

"I am gonna shower, get out."

"No, You get out."

You two glare at each other for a minute before you decide to fight fire with fire.

"Fine you can shower, but I am gonna shower too." You say, uncovering your nudity. "We can shower together, unless that bothers you?"

"Ha, bother me? Not in the slightest." He retorts. "Turn the water on already."

He is calling your bluff, but you refuse to lose. You turn around and bend over to turn the water on. Your ass pushes back against him. You feel his flaccid cock pressed between your ass cheeks, so you give your butt a little wiggle.

"Cut that out." He says.

You stand back up and turn the shower head on. Water starts raining down on you two.

"Can you hand me the shampoo?" You ask him.

"Get it yourself" He says.

You have to press your body against his to reach it, and again to put the bottle back. You close your eyes and lather your hair. You hear a fapping noise.

"What are you doing?" You ask, fearing the answer already.

"What I always do in the shower, Jerking off. You can leave if you don't like it." He says.

"Just keep it away from me." You say.

Now just wanting to end this shower before it gets out of hand you switch places with him. Doing so in this tight space is hard enough, but with you both being stubborn, you remain facing each other. This has the unfortunate side effect of his cock sliding between your legs. Due to you two trying to avoid that happening his cock slips inside your pussy. You gasp as it entered and again as it was removed. You are in complete shock and disgust at what just happened but before you bring it up, he says.

"Geez calm down, it's not like it went inside you or anything."

You realize he doesn't know that he just fucked his sister. Your disgust turns to confusion and slight anger. Your pussy isn't loose, he should have noticed, right? You push those thoughts aside as you scrub your body with soap. After you are full of soap, you ask to switch. This time you keep your back to him. You still end up with his cock between your legs since he still insisted on facing you. His cock once again pushes into your pussy.

"Damn, you don't need to squeeze your thighs together so tight, almost gonna break my dick." He says as you two fully switched places.

His cock wasn't in you long that time either but now you feel a bit better about your pussy's tightness. He goes back to jerking off as you rinse the soap off. Once you finish, you get caught up in everything and don't realize you can leave now. You tell him you are ready to switch. You two switch again, but this time back to back. He stands under the water facing you as he jerks off. You stand at the back of the shower getting cold.

"Hurry up." You say.

"It's kinda hard with your huge cow tits staring back at me." He says, giving one of your nipples a pinch.

You let out a moan and quickly cover your mouth with your hands.

"Uh... Jen, What the fuck was that noise?" He asks.

You pull your hands away from your mouth to answer.

"N-nothing, I was just surpri-" Your moan cuts off your sentence.

His hand stays on your breast this time. You have both of your hands pressed to you mouth. He keeps sliding his thumb back and forth over your erect nipple. You try to back away but end up falling on your butt and sliding under him, mostly between his legs. Except your face is pressed against his cock and balls.

"You okay?" Jason asks you.

"Yeah."

"That's a good look for you."

"Ah shut it."

"Are you okay in there?" Your dad shouts up to you.

You two without thinking yell back.

"Yeah dad!" at the same time.

"You guys in there... together?" Your dad questions

"Uh..." You say.

"Yeah, just like old times." Jason adds

"okay... Kinda weird though." He says confused.

You stand up and tell Jason he needs to cum already before Dad gets suspicious. He stands there like an idiot so you step up to him. Your breasts squish against his chest and you take his cock in hand.

"Jen what are you?"

"You weren't doing it fast enough, now hurry up and cum."

"Jen-"

"Cum for your little sister, please Jason. I want you to cum in me okay." You say in your sexiest voice.

"Oh god, I'm gonna cum."

"Yes big brother, I want to feel your cock in me again. I want you to cum in me." You say, getting a little too in to character.

You pull your hand away and turn around. You lean forward and use your smooth pussy to pleasure his cock. You grind yourself up and down his shaft.

"Again?" He mumbles questioningly.

You catch your mistake but try to play it off like it's part of the roll play sex talk.

"I want you to cum. Cover my insides with your-" You cut off your sentence when he grabs your hips.

He pulls you against him harder and he starts controlling the motion of your pussy against him. He is using you like a toy at this point. He himself gets carried away.

"Gonna cum, can I cum inside you?" He asks.

"Guys I gotta pee real quick, coming in" Your dad enters the bathroom.

You try to pull away from Jason as you stand up but he pulls you back. His cock enters you balls deep with a slap as your ass collides with his body. You stand as upright as you can. Jason, anticipating you making a sound wrapped one hand around your mouth while his other pulls you against him, his hand placed low where applying pressure to the point that you can feel the shape of his cock inside you. Jason's cock is pulsing inside you. You glance back at him but he just shakes his head and shrugs. You close your eyes and concentrate on the feeling of his cum flowing into you.

"You guys almost done? I need to take a shower soon." Your dad asks.

"Yeah, almost done." Jason says

"Oh Jen, I'm going to grab some food after my shower, You wanna come?" Your dad asks you.

"Yeah, Do you want to cum?" Jason asks you.

You shoot him a glare but his hands start moving. He drops his hand from your mouth and He toys with your nipple while his other hand plays with your clit.

"Y-yes daddy, I want to c-cum." You try to say in a normal voice.

Your dad flushes the toilet and Jason gets an idea. He Thrusts during the sound of the flush causing you to climax.

"OH FUCK!" You moan as you cum

"Sorry about that you guys." He says as he washes and leaves, thinking the toilet flushing was why you shouted.

You pull yourself away from Jason and tell him to get out. He does so laughing. You clean up and grab your phone and go to your room to get dressed.