Tropical Accident

I held still while her back arched and her mouth opened to let out a shriek of ecstasy. Afraid of someone else hearing her, I leaned in close and covered her mouth with my own. Her arms wrapped themselves around me and her legs tightened their hold as she rode out her orgasm.

When it was over, she let go and flopped down onto the floor, soaked in sweat and panting heavily. My mouth found itself a new partner in her left nipple, sucking and gently chewing on the pink nub of flesh. My hips were thrusting slowly, gently slowly pulling back a little before pushing back in.

I started to pick up speed when Janice found the strength to start massaging my scalp.

"Just... just go slow?" I answered that by holding both her hands above her head and driving in deep and hard. "Ok! Ok! Fine! Do what you want!"

With a pleased grin, I started to make my sister orgasm for a third time.

When I felt my balls churning, about to empty my cum for a second time, I told Janice as such. She was lying on the ground, recovering from her third orgasm, but my words caused her to stir.

"No- Gah- you have to pull ouuuuuuuttttt!" A fourth orgasm rocked through her thin body, and her body was once again beset by convulsions. These were weaker than the rest, she was already exhausted from her previous ones. I started to pump faster and faster, keeping her words in mind.

Just before I exploded, I pulled out of Janice's worn out cunt until only the tip remained. "Are you sure I have to pull out?"

"Ye-yeah." My sister weakly replies between gasps for air. "I'm... irregular, so... today might... not... safe day."

I figured that since she was irregular, it was more likely that she wouldn't get pregnant. I really wanted to cut in her again but I didn't want to increase the risk. I dipped back into her tunnel one last time, testing my limits of self control.

"Do..n't." Janice warned. "Not... inside..."

Teasingly, I flexed my dick. She started to shake her head and trying to push me off, and I relented.

I pulled out completely and stood up, my manhood twitching madly about to explode. I jacked myself off above my twin, and let my cream spray all over her prone body.

We cleaned up as best as we could after that, wiping up my cum with her white bikini top. Janice was too exhausted to stand up, so I had to carry her on my back while we walked out.

The girl at the stall gave a knowing smile when she saw us exit.

"Awfully long time to explore the caves." She cheekily said.

I could only reply with a nod while Janice buried her face into my back.

Janice was serious about that day being the last, saying that I would be getting her pregnant if it kept happening. I didn't really mind, seeing as my dick only found its way in her by accident.

Still, if I was particularly horny and had no other outlet I would often masturbate to that day at the beach.

On a side note, a very important reminder of that day wormed its way into our lives. Janice didn't show any symptoms at all. Her period not coming for four months was rare, but not unheard of. We thought nothing of it until she collapsed in the middle of the university parking lot headed for our dorms.

The doctor told her that she was pregnant. Our dad was pissed, and our mother was hysterical. Janice could only cry into my shoulder while I consoled her. She made up a lie that she met a foreign guy four months ago. She didn't even know his name or where he was from, she told our parents.

They were understanding, but from then on monitored Janice's every move. They pulled her out of college, and forced her to into a kind of house arrest until she gave birth. They were having problems on how to keep tabs on her, when I volunteered to move back home so I could always check up on Janice.

My parents were very surprised at how gentle and caring I was for my sister in her time of need, making sure that most of her pregnancy wants and cravings were fulfilled. I couldn't exactly tell them that it was because I was the father.