Lina, Stacy's sister

Lina walked into the kitchen, dumping her backpack on the floor before raising her hands comically in front of her face.

"Stace! Are you h- oh shit, Alex! Put some clothes on! I mean to each their own, but I did knock and all"

Alex jumped and tried to cover himself with a couch cushion.

"Relax", She said, "not like you have anything I haven't seen before."

"You have no idea", Alex mumbled.

"What did you say?" Lina asked as she stalked out of the kitchen. "Jeez, this place is a mess, I guess Stacy isn't around"

"No, no shes not. She had to take Alistair to the vet, something bit him."

As she walked through the kitchen toward the living room door, Alex realized she was heading his way and panicked, diving over the couch to hide himself. His heart pounded with fear.

She stepped around the couch with a phone in her hand snapping pictures as she yanked the pillow away. Humiliation wracked Alex, as he grabbed his junk with both hands to hide himself from her.

"Don't be coy, I know my sis doesn't take care of you the way you need. Let me show you a good time, I've had a crush of you for years and this is the most I've ever seen of you. Its not fair." She leaned against him on the couch whispering now. "You can have me however you want, I just want you inside me." She purred a little, biting his ear.

" I cant" he said, " It would be wrong" but he could already feel his dick growing firm. She slowly closed her eyes as she grabbed his wrist and slowly began to move his hand down the front of her pants.

He felt his dick go rigid "No its not safe" He said. "I can't, really I..." His speech paused mid sentence. The voice in the back of his mind spoke, but this time it came from his lips.

"...I want you from behind"

"that's it? the boys at school are way weirder than that, just dont put it in my ass. She pulled his hand up and spun away from him putting her palms flat on the coffee table.

Alex's body moved without him, he began to panic as the sensations flooded in and he understood that the parasite had control of his every move. He sat up on the couch, sitting behind Lina and began to pull her tight jeans down from her skinny frame. The pale skin of her ass seemed to glow in the low light. Alex screamed inside his head, but the only words that came out were: "You are gorgeous, I will make you mine"

Lina shuttered with that and said "You fucking better"

Alex looked down as his cock now fully erect revealed the translucent worm matter under the skin. His body gripped it by the base lightly stoking, squeezing out beads of the slick slime. His body stood up behind her drawing her attention as he gently put his hands on her hips. Lina looked up at his face. He wanted to reach out to her as their eyes met but she could only see the thing's smile. Her neck was craned but the parasite was behind her supple ass preparing to penetrate her.

"This may feel a little strange" The creature said