Show her what real dick means

You pull back from the kiss and Keira immediately pulls her sodden joggers off and starts gripping her nethers for dear life.

No no no, that won't do at all. She needs to learn that her hole is only for you, no clumsy hands or baby boydicks allowed.

You push her hands aside and show her how its done, rubbing her clit expertly until she cries out and collapses towards you.

Gripping her tightly you whisper, "I’m going to fuck you Keira, take my big 12 inch dick and don't fight"

Pinning her wrists above her head you align your fearsome weapon with her comically undersized little slit.
You gently tease her entrance with you brutal cocktip. Bullying her little nub and slowly spreading her all too tight hole in playful little motions. Her womanhood weeps its need in response, soaking the bed and screaming to be used by the massive lance before it.

With a show like that, why deny it? You cease your torturous **** and give Keira a quick peck on the forehead, she'll need to be a little distracted for what comes next.

Your hips press forward feeding inch after inch of your monstrous endowment into your sisters brutally strained orifice. Her lips stretch painfully tight around your inhuman length as you irreverently advance into your sister's most sacred place.

She is by far the tightest hole you've ever had. James really must be pathetically lacking. It feels like your cock is being gripped by a thousand rubber bands around a sheath made of hot wet silk. But continue you must.

You slam forward until you can't anymore, hitting her cervix and stopping for now. She starts quivering instantly, the sensation overwhelming her. She doesn't know what she's in for if that was too much already.

Turning her over you cover her mouth, you have enough experience to know what kind of response your cock is about to elicit. You start mercilessly marching into her innards over and over again with your massive member. Her vice like tunnel gripping your meat for dear life as it reshapes her from the inside out.

Over and over again, faster and faster, beating her cervix into submission until it opens up and lets the last quarter of your cock inside. You feel your cockhead spear inside her womb, the new sensation divine enough for you to pause for just a moment. Your meaty spire proudly belches a cup of clear nectar into its newly won territory, claiming it. But this moment of peace can't last long.

Your sister needs to remember this. This memory needs to be burned into her very soul for the rest of her life. From now on sex with anyone else will be meaningless, she needs to be yours forever. To learn the truth about just how perfect your cock is and how much it can change her life.

All this time she shakes and screams against your grip, absolutely lost in the highest form of rapture. But still she needs to be taken higher. Your proud pulsing pussy-punisher punches into her pelvis even faster.

Nearing release, you can't help but let loose just a bit. You doubt she'll be able to feel too much pain through all that pleasure, and even if she does, you doubt she'll care. Regardless, you feel the end approaching.

The bobbing of your plum sized nuts marks the end of this incestuous union, and your heart races as you feel release take you. Your shaft bulges absurdly as a load of cum that'd put horses to shame barrels up your excessive endowment. Your sisters screaming cunny stretches further as your cock reaches a new level of thickness from the impending torrent and the effects of climax.

Your sister screams in blended ecstasy from the painful sensation. Being stretched even further than the new maximum your merciless member **** upon her.

Your cockhead finally releases its first shot, and overwhelming relief washes over you as your cock assaults your sister's insides with wave after wave of thick boiling seed, each pulse ten times the load of a normal man. Shot after shot of your dense virile cream punches into your sister's newly opened womb as your vicious mating finally comes to a close, her stomach bulging and hole leaking from the ridiculous excess of your gift.

Finally you pull out from her, your semi-flaccid cock still a sight to behold. Glistening with mixed fluids and still quite near a foot in in length, you slap your weighty slickened pride on your sister's face like newly conquered prey.

She has quite the mess to clean up.