You decline, which Sarah does not take well

You shake your head vigorously, ridiculous as it sounds you were caught up in the mood. Imagine, you almost let your younger sister ram her cock up your ass.

You unwrap yourself from her and stand up, Sarah looks at you with dismay, your actions revealing your answer before you could even say it.

“Sorry Sarah… I just don’t think this is a good idea.”

Sarah’s face is downcast as you shuffle past her to turn off the water, you’d been in here too long. You stop with a yelp as two small hands grab you and pull you back. You look at Sarah, tears noticeable in her eyes despite the mist from the showerhead.

“You’re wrong” she sniffles, as she pushes you down. You try to remain standing, but the shock caused by her actions, and the wetness of the floor prevent you from resisting. “We’re perfect for each other Doug, after all we’ve done you still don’t see this?”

You begin to plead, but are instantly interrupted as her massive member pushes up against yours. “I understand now” she glowers “I just have to take charge, after I cum inside you you’ll agree with me!”

Sarah’s cock rubs against your own as she pulls her hips back. You once again try to resist despite her shemale strength you’re still older, and should be able to beat her, but the ground is slippery, and you have no leverage in this position. You begin to wiggle your hips in a last ditch effort to prevent her intrusion, an act that frustrates Sarah further.

“Doug, just accept it, I know what you need.” She moves her hands to your hips preventing further movement, her cock presses against your backdoor and she begins to push. You clench as hard as you can to keep her out, but she begins to rock back and forth, slowly wearing down your resistance.

You cry out “Sarah, please! You’re not thinking straight, let’s just talk about this for a minute”.

Your pleas are ignored as Sarah begins to push harder, she grits her teeth and growls “Just. Let. Me. IN!” With that your asshole gives out, and Sarah plunges her cock into you. Barely any of her cock manages to penetrate you, but it is enough to make you cry out in alarm, your hands buckle from under you as Sarah sighs. Not satisfied with her current depth she pulls her hips back and slams into you again. She does this over and over, slowly stretching you to accommodate her full member. You squeak and groan as she does, your hands now covering your mouth to prevent the rest of your family from hearing you.

After what seems like an eternity Sarah hilts inside you, her massive balls resting against your modest ones, the heat from them, and the feeling of shame over her complete dominance over you, bring your cock to an erection. Sarah notices this and smiles “I should have listened to Crystal in the first place “Boys are never going to make the first move, above all else they love to be dominated by the woman they want”” She pulls out till just her head is inside you and then shoves her cock balls deep again.

As Sarah finds a rhythm you blush, as much as you want to be outraged, as much as you want to fight back, you can’t. You’re enjoying, being completely dominated by your little sister, despite everything. Now that the initial shock has worn off you could fairly easily resist if you truly wanted to, knowing this helps you accept what is happening.

You cum, a final groan issuing from your lips as you do. Sarah follows a few moments later, hilting one final time and unleashing a torrent into you. She sighs as the last spurts jet from her cock, and then slowly pulls out of you. You remain as you are, secretly basking in the afterglow, your ass in the air and overflowing with your sister’s jizz. She pats your ass and smugly declares “See? You loved it, don’t worry, we’ll do a lot more later, we have to get out of the shower now though.” With that she rinses off once last time and leaves the shower.

You stay there a little longer, both enjoying the feel of her cum flowing out of you, but also thinking about what this means. You’re too exhausted to talk to Sarah about it tonight, you figure you’ll be able to deal with her after a night of rest. With that final thought you do your best pushing as much cum out of you as you can, then you head off to bed.