Chapter 3: Menstruation cycle and Ovulation day
He embraced his sister in his arms.
「Uu……」
His sister let out a short, seductive moan.
He mounted his sister and sucked on her nape. His right hand pressed against his sisters left breast and fondled it over and over again.
「A,ahh」
His sister pants.
He keeps crawling from his sister’s nape to the jaw and her lips.
After staring at each other for a moment, their lips overlapped. Bolder than in the evening, they sucked on each others mouthes deeply and intensely.
「N…….。 Nn……」
A seductive sound continued to leak from his sister’s nose. Judging from the tone, he understood that his sister is soaked in pleasure.
Saliva flows into his sister’s mouth in succession. His sister sometimes gulped, she drank the saliva that gathered in her mouth.
When he released his mouth, his sister leaked a sigh of ecstasy.
「Aahh……」
His sister’s breaths covered his face. His head turned dizzy to that sweet scent. He couldn’t endure any longer and extended his tongue to lick the inside of his sister’s mouth all over.
Palate. Inner cheek. The bottom of the tongue. The other side of the teeth…….。
(I wonder why am I doing this……)
Though he’s drowned in ecstasy, somewhere in his head is still awake.
(Isn’t the one I lust for insatiably right now my true blood-related sister? Just half a day before, wasn’t she a helpful and ideal sister? Is it okay for me to do this kind of thing?)
「Ahn……, aah……, uu……, Nozomu……」
The writhe of his sister increases his intensity gradually.
(No matter how you look at Nee-chan, she’s feeling good……。 This might be okay)
「Aahh……, Aahn……」
The little reasoning remaining in his head, they almost got blown off.
Raising his upper body a little, he started to undress his sister’s sweatshirt. His sister Banzai’ed on her own. Did she want to undress quickly? He rolled up his sister’s sweatshirt in a hurry.
There was no bra. In the dim light, her areola and nipples could be seen standing out. Though they stretched to the sides because she was lying face up, there’s no doubt that her big breasts’ size was just right. Fighting down the impulse of wanting to suck them, he continued to strip her.
Her armpit hair was beautifully dealt with. Her long black hair was pulled by the sweatshirt, then it spread on the bed in fan-form. Pulling the sweatshirt off from her arms, he completely stripped her, then dropped the sweatshirt on the floor.
The half-naked sister raised her hands as if wanting to cling, then stretched her arms in solemn. She closed her eyes, became limp, and entrusted her body to her little brother.
Beautiful…….。
He also took off his long-sleeved T-shirt hurriedly, and became half-naked.
He mounted his sister and brought his body close to her. His sister’s temperature was transmitted directly through her soft skin. He closely clung to the moistened skin of his sister.
It was the kind of pleasure that made him dizzy……。
Pressing his lips to the nape of his sister, his right hand wrapped his sister’s left boob and massaged it.
「N…….。 Nozomu……」
While hearing his sister’s panting voice, the horny impulses inside him arose irresistibly.
「Nee-chan! Is it okay for me to lick your body!?」
「Eh? It’s alright but……」
He crawled his lips on his sister’s skin. Head to shoulders, passing through the collarbone, then he reached her armpit. Extending his tongue, he licks her armpit.
「Ahh！ Nozomu！ Aaah！」
Surprised by the intense reaction of his sister, he let go of his sister’s body and looked at her face.
「Wh、What’s wrong？ Licking is no good after all？」
「Sorry, It’s nothing. I’m just a little surprised. Don’t mind it, do continue」
Mounting her again, he extended his tongue and went back to licking around his sister’s body.
Armpit. Upper arm. Shoulder. Collarbone. Throat and neck. Nape. Earlobe.
Forehead. Nose bridge. Upper lip. Lips. Cheek. Chin.
Oppai.1 Nipple. Around the navel. Flank.
He carefully licked around the front of his sister’s upper body.
「Aah……。 Nozomu……」
(Delicious……)
His sister’s skin has a sweet and a delicate saltiness, it was a very good flavor.
The whole upper body of his sister started to glitter because of the smeared saliva. Raising her upper body, he gazed at his sister’s sublime shining body.
He once again covered her body slowly, and brought his body closer to her. Their lips overlapped and their tongues entwined.
After a while, their mouths separated, while smelling each other’s breaths, they stared at each other at point-blank range.
「Nozomu。 Take off the lower half too」
「Is that okay?」
「It’s alright……。 Take everything off」
「Everything you say……」
「Are you a virgin?」
「Yeah……」
「Me too。 I’m a virgin」
「Is it okay？ For me」
「I said、it’s okay if it’s you。 Before a weird man steals it」
「But……。 We’re siblings you know？ It’s dangerous if you get pregnant right？」
「Since my menstruation is in about one week, it’s okay」
「Is that so?」
「I measure my basal body temperature everyday」
「Basal body temperature? 」
「One week ago was ovulation day it seemed. My menstruation cycle is exactly four weeks」
Nozomu still doesn’t know much about the woman body.
While pinning down his sister, they stared at each other at a distance in which their noses could touch, they continue their conversation. Sometimes, as if they just remembered, they piled their lips.
「You’ll get pregnant if you’re on ovulation day?」
「Because sperm can live inside the Fallopian tubes of the womb up to around 3 days」2
「Up to three days?」
「Though healthy sperms might live longer」
「Around a week?」
「Right……。 An ovule when ovulated from the ovary seems to be there for about 24 hours」
「For 24 hours……」
「However, it’s not that it can always be fertilized, it seems to be more restricted in terms of when it could be fertilized」
「It’s restricted huh……」
「That’s why timing is important」
「Timing……」
「From the ovulation day around a week ago, it might still be dangerous without contraception 2 or 3 days after that」
「Contraception……。 It’s still necessary after 2 or 3 days after ovulation day?」
「Because you can’t exactly pin down the time for ovulation. You can’t see it with your eyes after all。 In the end, we can only make a rough guess for an estimated day。 I don’t have control over the freedom of time you see」
「I see……。 How is contraception done?」
「As expected、should be a condom……。 I’ll buy it next time」
「I can’t just cum outside？」
Nozomu has some form of knowledge regarding sex from ero books and porn videos. There’s also a lot of it being based on the desires and delusions of man.
「Though you say cumming outside, there are a lot of times you’d leak a bit inside you know」
「Is that so?」
「That is why when the probability of being pregnant is high, a condom is necessary after all」
「Condom, huh……」
He couldn’t believe the day he has to use a condom……。
Moreover, his partner is his sister!
「Anyway, I won’t get pregnant even if you ejaculate inside today」
「E-ejaculate inside」
「Yeah. Since it’s a first experience for both of us, don’t you agree that it will become a memory of a lifetime?」
「That’s right」
「At times like that, if you worry about the likes of contraception, won’t it damage the memory?」
「That is right」
「That’s why, you don’t have to worry about contraception today」
「I see……」
「Now take everything off」