After a couple of days of staying together the two girls started getting closer to Arthur, they talked a lot since there wasn't really anything else to do and started to feel comfortable around him and sometimes they would even make out a little.
Apparently they are staying here because they were going to the college nearby, but their family lives a couple cityes away but it was almost impossible to get there only the two of them.
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"Hey, what are you cooking? It smells incredible!" Asked Emma. Neither of the girls knew how to cook and Arthur's cooking was a blessing sent from the gods, they never tasted anything like it their entire life.
"I'm just making some spaghetti, I would say they are my best dish."
"Best dish?!" Her mouth was watering and her legs almost gave out from just the thought that he was making something even better than what he made up until now. "D-do you need any help?"
"No, but thank you, it will be ready in 5 minutes, go tell your sister to get ready"
"Yes, chef!" She replied while saluting Arthur, he found it very cute and he gave her a little kiss.
"Hey! Not fair, why am I always left out!" Said Rebecca while crossings her arms and puffing a little.
"Sorry, I didn't mean to, the food will be ready in 5 minutes." Said Arthur before kissing her too.
"What are you making?
"He's making spaghetti, sis, and he said it's his best dish! I can't wait to try it!"
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After eating, the three of them laid on one of the beds and started kissing. At first Arthur and Emma were kissing. "Art, me too." Then he started making out with Rebecca.
Emma, not wanting to wait for her turn, put her hand in Art's pants and took out his big dick. "Holy cow, it's sooooo big!"
It was the first time she saw it since they never went this far, but Emma was particularly horny tonight. At first she just rubbed it with her hand, but because Arthur didn't show that big of a reaction she started licking it, and then she put the tip in her mouth as she was getting her clothes off.
Seeing that, Rebecca didn't want to be left out and she also took her clothes off. They were both sucking Art's dick and he was close to cumming since he didn't jerk off for almost a month.
"I'm cumming!" After he said that, Emma quickly put it in her mouth but there was so much semen that she couldn't drink it all and even choke a little on it. But something unexpected happened, her eyes started to glow blue for a second.
"Wow, I feel refreshed after drinking all that."
The other two looked at her a little before continuing, Rebecca couldn't wait anymore and stood above the long rod that was still standing proudly and she started lowering her hips. When the tip was touching her pink pussy she stopped for a second. "Don't move, it's my first time."
After saying that she lowered her hips again and the hot rod entered her until it hit a wall, she didn't seem to want to move anymore so Art gave her a little hand by pushing her hips down and the little wall was torn apart. "Augh."
He moved his hands a little higher to her pink nipples and started rubbing them while Rebecca began to move up and down. While all of this was happening Emma was almost sleeping and her eyes were glowing a little, and at a speed almost visible to the human eye she started to grow in height a little, her skin bacame softer and without imperfections and her breast grew all the way to D Cup. When she woke up, she saw that Art and Rebecca were almost done, she waited for her sister to get down from that massive rod after Arthur shot the white stuffing inside her and without warning she took Rebecca's place, not hesitating to tear her hymen apart. Art didn't complain and started moving his hips too and they climaxed together, after that Emma laid on the bed on the other side of Art than her sister and fell asleep.
He saw that Emma's body has changed after she drank his cum and he wondered if the same was going to happen to Rebecca.
'I guess I'll have to wait and see for myself, at the end of the day flat is justice, but medium is premium. I wouldn't mind either way. But I better take a shower, I stink.'
After he entered the shower Rebecca woke up and decided to join Art, her body didn't change that much compared to her sister, while Emma was almost as tall as Art she only grew a couple centimeters and her breasts didn't grow at all, but the other features her gained seemed lacking compared to her, her skin was incredibly soft and her beauty amplified by almost 4 times, you would mistake her for a perfect doll bade by the best master out there if she didn't move. A while after joining Art in the shower Emma also woke up and joined them, what continued were a couple of days of almost constant sex between these three teenagers in heat, the only pauses were when Arthur cooked for them since they didn't want to make him mess up his delicious food.