You reach the cave, and you try to help the poor mermaid asking for help.
Once you are inside the cave, the mermaid calms down.

She says that you saved her life because she was trapped in the cave and will never experience sex. She asks you if you can help her... because it's her first time.
Her voice is melodic and beautiful... you can't say no!
The mermaid adopts human form, she is even more beautiful now, you sense a strong erection and you are ready.

You slowly stimulate her big breasts and pussy, and you share a passionate moment, he enjoys the sex with you and says that you are awesome.
Now he has her eggs ready inside her.
You are confused...

From between her legs emerges an ovipositor, smooth and menacing. It is an extension of her, and she looks at your naked body.

Because of her inexperience and excitement, he accidentally releases the charm spell on you.
You understand everything now, she tricked you into getting inside the cavern and taking advantage of you.
The mermaid doesn't know much about humans, and she doesn't understand why you have only "one hole" down there, but it will be enough for her.
She slips the ovipositor inside your ass, and you feel a strange sensation, not pain... it's just invasion and humiliation.

The mermaid starts to fuck you, you are too weak because of the spell and you can't resist or fight back, you can just beg her.
You feel the ovipositor going deeper and deeper inside your body.

Her muscles start to push the eggs out of her through the ovipositor, and she experiences extreme pleasure when the eggs pass her pussy. You can see the pleasure she’s experiencing by her moans, her body trembling and her drool dripping on your back.

She cums multiple times laying the eggs inside you, and you think that she's losing her mind... no matter how much you beg, she continues the process and you feel an intense pain in your belly, it's hard to breathe and you are in panic.

After uncountable orgasms, the mermaid it's about to faint, her body can't endure the shock of pleasure. You also reach your limit, your belly is so swollen, that you look like a 9-month pregnant woman... your belly is so heavy that you can't stand up.

The mermaid is exhausted, she faints and adopts her mermaid form again. You breathe slowly, the pain is too much and you think that you are going to die. You feel a few eggs slipping through your ass. Trembling, with cold, you lose control of your body.
You listen to other mermaids talking, saying that her first time was intense. You are stunned and you can see only shadows and muffled voices around you.
You feel pain in your ass and you notice that another mermaid plugged your ass with some kind of slimy and sticky fluid, like a spiderweb, and you faint.

You wake up, hanging from the cave, with horror you observe your bloated belly, it's so huge that you can't believe that you are still alive. You also notice other male and female humans hanging from the cave, upside down, and with their bellies as full as you.

You are charmed by the mermaid's song, it' helps you to ease the pain. Every day you notice your belly bigger and bigger.
One day, not even the song of the mermaids is helping you to endure the pain, you think that your body is going to burst. You a strong orgasm, your limp cock starts to cum... you feel a sharp pain inside you and everything is black... the pain is over.

THE END

Task: Act charmed and happy. Put a lubed rubber pussy in the fridge for a few minutes. Imagine the mermaid and fuck the rubber pussy for 5 minutes (don’t cum). Imagine that she releases the spell and act frightened and weak. Insert a very soft long dildo as deep as possible (it’s suggested a 40cm dildo or more, like a “colon snake”). Slowly move the dildo to invade your inside and reach deeper and deeper. Beg her to stop. Take it off and insert 5 ice cubes in your ass with 1500ml of warm water. Hold your belly and moan in pain. Insert 5 more ice cubes. Plug your ass with a big buttplug or inflatable buttplug. Listen to a charming song and hold your belly inside the bathtub (upside down) it must be uncomfortable. Rub your clitty and cum over yourself. Release in the toilet after 10 minutes.