Amy's Step Sister #4

Note : This story is completely fictional!

Up in Kaitlyn's room, both girls had stripped naked. They lay on the bed holding each other, kissing and hugging. Amy was playing with her sister's big titties, which made her start feeling horny again.
"Amy?"
"Yeah?"
"Will you play with my butt like I did yours?" Kaitlyn asked, almost as tentatively as Amy had asked her a few days ago. "Of course I will, silly. I've been wanting to put my finger in your bottom for weeks." Kaitlyn got up on all fours and dropped her shoulders to the bed, so that her ass protruded up. She reached behind her and pulled her cheeks apart.

Amy decided her sister’s butt looked so good, she wanted to kiss it. She knelt between Kaitlyn's feet and put her face to her big sister's butt-hole. She puckered up and kissed it with a resounding pop. Shivers ran down Kaitlyn's spine. No one had ever done this to her before. The sensations were completely foreign, but wonderful. She felt what must be her little sister's tongue licking around her ass pucker. Then the tip pushed into her. The feelings were so strong; it was hard for her to relax her anus. She wondered if she would be able to take even her sister's little fingers.

Amy put KY on her first two fingers. She pushed one, then the other into her sister's firm butt. As she began to wiggle them around until she felt her sister's bum begin to relax. She pulled her fingers back out and slid her head under her sister's crotch. She playfully flicked her sister's clit with her tongue. Kaitlyn loved having her clit licked. And her sister was becoming an expert. She felt her orgasm approaching. Then Amy shoved her first two fingers back into Kaitlyn's anus. She immediately lost all control and spasmed in a relentless orgasm.

Amy watched her sister spasming above her. She wished she could have put ALL her fingers in her sister's bottom. And she wanted more in her own. When Kaitlyn had rolled off of her, she got up and went to her big sister's hiding place and returned with the vibrator. She waited for her sister to recover before she handed it to her.

"You want me to use this on you? You are a horny little girl aren't you? Have you ever had anything in your pussy before?"

"I don't want it in my pussy. I want you to put it in my bottom." Kaitlyn looked at her insatiable little sister and wondered briefly if her little butt would ever get enough. "Alright, but you have to ask right." Kaitlyn snickered. "What do I say?" Amy wanted to know. "Say 'I want you to shove it up my butt.” Kaitlyn said.

The little girl seemed to struggle with the idea at first, then decided it made her feel more dirty and made the whole thing more exciting. "Kaitlyn, I want you to shove that vibrator up my butt. Shove it in as hard and deep as you can."

Kaitlyn was surprised that she picked up on this so fast. It thrilled her to hear her sister talking so dirty. Amy got on her knees on the thick carpet and leaned over a smooth cedar chest at the foot of her sister's bed. Her butt was now spread and easily accessible to Kaitlyn's probing. Kaitlyn spread KY all over the 1-1/2 inch thick vibrator. She knelt behind her little sister. She caressed Amy's buttocks with one hand then pulled them apart. She placed the tip of the vibrator against her sister's already loosened little ass-hole.

Amy felt so open and vulnerable like this. It made her feel tingly. She felt the cold tip of the instrument at her butt-hole. She remembered words she had heard her sister use. "Fuck me, sis. Shove that big cock up my ass." Talking dirty made her feel even sexier. Kaitlyn slowly slid the tip into her sister's anus. Amy moaned with pleasure. Already she was feeling more stretched than she had earlier. It felt incredible.

After several reassuring moans from Amy, Kaitlyn slid the rest of the white vibrator into her sister's rectum in one long stroke. Even Amy's immature bowels almost swallowed the thing completely, and Kaitlyn had to be careful to have enough to hold on to. She pulled it back out again, then placed the tip against Amy's sphincter and shoved it back in, harder and faster than the first time. Amy's moaning increased each time the speed of the entry increased. Soon Kaitlyn was pounding her sister's 18 year-old butt-hole at a fever pitch.

Amy couldn't believe the sensations. She had never felt so full, so complete, and so incredibly wonderful. She moaned louder and louder each time her big sister pounded her stretched little asshole. Kaitlyn stopped for just a second, and when she resumed, Amy realized she had turned on the vibrator! The sensations were suddenly too much for her, and her mind went reeling as her body felt previously unknown pleasures.

When Kaitlyn finally stopped shoving the vibrator mercilessly into her sister, she realized that she must have passed out from her orgasm. She wondered what that would be like. She decided she would have to try this too. For now, though, her little sister was completely exhausted and needed some rest. She wiped the grease from Amy's butt, and then carried her to her room and put her to bed.