I leap into the pool, paddling my arms and kicking my legs until I touched the bottom. Heh, I guess I'm the only one left in the family who has legs. So much for that: by the time I reach the surface again, my lower half has transformed into a tail. My scales are a deep crimson, glimmering in the sun. Like Lauren, my mother, and Anna, my sister, I can breathe both water and air. Unlike them, I can revert to human form. Somebody needs to, whenever somebody comes to the store, or we need something from town. But for now, I've enslaved my mother and my sister, transforming them into mermaids. It seems only fair that I should join the mer-family, at least for a while.
I swim up to my mother. Her face is a mask of absolute contempt. "Oh, Jake," she says. "I never showed you anything but motherly love. Why would you do this to me?"
"Why does a man do anything with a beautiful woman?" I shrug for her. "Yes, you showed me love, and now I've shown you lust. Why can't you be happy for me, Lauren? Your little boy's all grown up, and he's taken himself a wife. Two wives." I've given all three of us powerful sex drives, and I'm already hard again. I wrap my arms around my mother's waist, resting my pounding erection against my mother's already incestuously violated slit. Lauren's body feels so good with her breasts pressed into me, and I stroke her back in long, slow, sensuous strokes.
"We can't be your wives. We're your mother and your sister. This is sick. You've raped your own mother, and your own sister. You can't come back from something like this, Jake."
I sigh, my shoulders drooping, and release my mother from my lustful grasp. "You know, Lauren, I can simply change your mind for you. I have that power. I've already overwhelmed you with such lust that you begged your own son to enter your body."
"Yes, don't you see? That's the problem! For all we know, I'm already pregnant. Maybe your sister is, too."
"I can change your mind for you, Mom," I say again, "but I don't want to. I want you to come into this willingly. I want you to long for me like I long for you." I push away from my mother and swim over to where my sister still lies poolside, exhausted from the mind-blowing orgasm I gave her. "Anna's happy I've done this thing to her. Aren't you, Anna?" I reach up and stroke her naked breast; her nipple hardens under my hand.
Anna just smiles, arching her back and giving something of a purr.
An idea strikes me. "Anna," I say. "Our mother has an immense sex drive, but she's averse to actually having sex with the one man who loves her most. Why don't you slip into the water here and persuade her that incest is allowable in a mer-family?"
Anna opens her eyes to look at me, then looks over at our mother. Lauren looks confused at first, but when she sees me stroking Anna's body, and Anna's intense, post-orgasmic expression, she realizes exactly what I mean. "No, Anna, you can't," she pleads. "I'm your own mother."
Anna never utters a word; she just rolls over and slides into the water with hardly a plop, like she's been a mermaid her entire life. She glides under the surface, right up to Lauren. Then she surprises me by not surfacing. I'd expected her to try kissing Mom's mouth and stroking her breasts, like I did. But maybe it's different between women, who knows.
My sister, whose pussy I just pounded, is below the surface, giving our mother oral.
Lauren's back arches, and she grips both hands on the edge of the pool behind her. "Oh! No! Anna! Please! Oh! Stop"
But Anna's beneath the surface, giving Mom's cunt the perfect tonguing, and can't hear Mom's protests.
"Anna! Please! I'm your, oh, I'm your mother! Oh! Please! Don't do this!" But despite her protests, Lauren starts bucking, and wraps her tail around her daughter's neck, pressing Anna's face into aroused Mommy pussy. "Anna! Oh! Oh my God! It feels so good!" Mom's face is a mix of complete ecstasy and absolute self-loathing. She's already begged for her son's cock, and now her daughter's tongue is wrapped around her clit, and she's loving it.
At last, Mom's orgasm hits. She lets go of the pool's edge and sinks to the bottom of the water, her tail still wrapped around Anna's neck, her face the image of absolute bliss.
Anna and I may not have changed our mermaid mother's mind, but we've certainly persuaded her body. Before long, she'll be a complete incest addict.
I swim down to the bottom and smile my thanks to Anna, who has just extricated herself from our mother's lustful grip. I stroke my big sister's breasts and hair.
I've probably already made my mermaid mother pregnant. Now it's time to think about breeding my big sister.