2T4U/Jack/Raped Melony/Missy's room (P)/gentle/You've been taking it slow long enough, just push through
"I thought you were a big girl? Do we have to stop?"
"I am a big girl! I can do it, you just—Ah!"
You cut her off with a hard thrust as your dick sinks another inch deeper. Missy tries to finish what she was saying, but you force yourself in to the halfway point. She tries to speak one more time, but she has to focus more on just breathing. She's so tight, you also need a moment to get used to the vice grip she has on your member. After a few long seconds, her breathing stabilizes somewhat and more importantly her vaginal walls relax.
She takes a deep breath. "You're so—"
No time for talking, you thrust again and sink another inch before bottoming out. You've got five and a half inches buried in your six year old sister. If you were an average man, she may have been able to take your whole length, but you still have two of your seven inches left outside of her. Her breathing has gotten real shallow now as she accommodates your size. Slowly, you pull out half an inch and move back in. With slow, short movements you build up to pistoning almost your entire length as her breathing synchronizes with your thrusts.
"Ho ho ho ho" She begins quietly vocalizing, growing accustomed to your intrusion. "Ah! Ah ah ah!" You pick up the pace and she gets louder. "Yes! Yes! Yes!" Your tiny first grader sister is getting into it. You keep going faster. "So. This. Is. Sex." She finally manages to say something in spite of your assault. "Sex. Sex Se-ex." She repeats. You could tell she thought the word was naughty and she probably wouldn't have even been allowed to say 'sex' yesterday, but something definitely changed this morning. "SEX!" she shouted again and the word rippled through her pussy.
"There's a really naughty word for sex. Do you want to know it?" you ask her.
She just nods her head. You can see her holding back her voice, desperate to hear this new word.
"It's the F-word, 'Fuck'. I'm fucking you right now. I'm fucking my little sister."
"Fuck!" Her voice rang out bright and cheery. "Fuck!" You feel like her pussy got ten degrees hotter. "Fuck!" You feel her love juices squirting out on your balls every time you trust into her and they start to drip from your sac onto the floor. "Fuck me! Fuck me to my tum-my!" You start pounding her as hard and fast as you can. "Fuck! Fuck! Fuck fuck fuckfuck Fufufuuuu..." Her words blend into a single groan and her limbs start flailing about, splashing in the urine soaked sheets. You can't move. Her pussy clamps down so tight you just hope she doesn't hurt you. Even with how wet she continues to get, with juices squirting around your union, you don't dare to even try to move. You just have to wait out her orgasm.
Eventually she goes limp. She tries to roll over with your dick still inside her and you think you hear her whisper, "Thanks" before falling asleep in the puddle of your and her own pee. Unfortunately, she came before you did and now you're as horny and frustrated as ever.