Christmas Eve...
Peter adjusted to the jock lifestyle faster than he would have expected, ironically because he was a box turtle now. But just because he was a turtle now didn't mean he moved slowly. Well, he couldn't run as fast as some other guys, especially other Animalians, but he was definitely of the 'mighty glacier category'. The impressive set of muscles he gained when he was double-dosed only continued to build up as he lifted weights in the gym and trained for the bodybuilding competition. He couldn't wait for the martial arts dojo to open so he could do some real training.
It certainly helped that he had his own personal harem of beautiful turtle girls. Lina, Reva, Dela, and Mara were very amiable towards each other and didn't mind sharing Peter between them. There was more than enough Peter to go around. But in the back of his mind, Peter knew this fantasy life couldn't last. Eventually, he'd have to pick one girl to be his official mate. Though it was pretty hard to pick among them. He assured himself that the choice won't be for a few more years. One or two of them might notice another turtle Animalian and reduce his choices a bit. But Peter was extremely content to have the four of them to himself for now.
When Christmastime came, Peter honestly wasn't sure what he'd be getting. Ok, he was expecting a few video games and some exercise equipment, but with his turtle girls, he was pretty content. He did do quite a bit of shopping for the turtle girls. A lot of it was specialized clothes. With turtle Animalians, clothing was a bit arbitrary as their shells covered up plenty and they could easily remove them once they've had their second dose. But the sensitives of humans had to be observed and a special design of clothing was made for the turtles. To be honest, the clothing were more like pieces of cloth to stick over the front of their shells and covered up some of their limbs. It was rather like dressing up 3D paper dolls. But the girls liked their clothes and Peter obliged.
When Christmas Eve came, the turtles were all excited to open their presents. Oddly though, Peter's parents hadn't talked much about what they wanted for Christmas. Whenever Peter asked, they just said 'Just wait a little longer'. Well, now it was Christmas Eve and Peter still hadn't been told what they wanted. He was freaking out a bit that his parents wouldn't be getting anything at all.
Considering Peter was such a pathetic example of a nerd, his parents weren't the best genetic stock either. His mother, Fran, was where Peter got his curly red hair, his pasty, pimply complexion, and his asthma. His father, Carl, was where he got his very poor eyesight, his less-than-stellar physique, and his bad teeth. Most people assumed that they married because nobody else would have them, but they had a very strong love for each other and their son. They were very proud that their son not only was comfortable with his new species, but that he was excelling in physical activities and had four nice girls who loved him. Some parents would question letting their children have a harem, but as long as Peter was happy, they were happy.
As such, Peter felt rather indebted to them and really wanted to find a good Christmas present for them. But their unusual tight-lipped responses left him guessing. He did manage to get them DVDs he was sure they'd like, but he wished he could have gotten them something more personal. The girls didn't seem as worried, but Peter chalked that up to it being their first Christmas.
On Christmas Eve, there was plenty of present-opening, but most of it was for Peter and the girls. In fact, the only things that were for his parents were the DVDs Peter had got them. "Sorry, guys, I wished I could have gotten you something better," said Peter.
"It's quite alright, Peter," said Carl.
"We actually have a very special gift coming," said Fran.
"And it's from all of us," said Dela.
"Wait, what?" asked Peter.
"We wanted it to be a surprise," said Reva.
"A surprise just for me it looks like," said Peter.
"Well, we could have let you in, but it would have been less fun," said Mara.
"So what's the surprise?" asked Peter.
"Right here," said Lina as she walked with two tall green glasses were filled with green milkshakes. They looked quite cold from the way they were giving off mist.
"That's the big surprise?" asked Peter as Lina handed his parents the glasses, "Pistachio milkshakes?"
"Pistachio milkshakes made with extra special milk," said Dela coyly.
Peter paused and looked at the four turtles before saying, "Did you really..."
"Yes, you were having such a good time as a turtle that we thought we should do it ourselves," said Carl.
"We ought to be one big family," said Fran. With that, the two of them took long sips from their milkshakes, though they soon stopped and cringed from the coldness.
It didn't take long for the milkshakes to take effect. A green tinge spread over Peter's parents as their skin became covered in scales. Quite soon, their faces started to distort as they started to form into the characteristic beaks of turtles. Carl's glasses were knocked off as his ears became small holes, not that his improving eyes would need them anymore. Fran's breathing quickened at first as if she was suffering an asthma attack, but then her breaths became a lot deeper. Their clothes soon started to tear apart as their torsos bulked, namely because of the shells that were growing from their bodies. Pretty soon, they were torn asunder, their new plastrons preserving their modesty.
Peter stared in surprise at his altered parents, now anthro turtles like him. "Wow," he said, "You guys look awesome."
"You can see why we didn't ask for anything specific," said Carl.
"We couldn't have anything until we had our final measurements," said Fran.
"What do you mean by-" started Peter when Carl and Fran traded glasses and took a longer sip.
"Each glass has milk from two of us," explained Mara, "They wouldn't get a second dose if we all poured into one."
Peter turned back to look at his parents and saw them begin to bulk up. They weren't exactly frail after their first change, but this was going far past that. Carl's muscles built up to his son's level before surpassing it, the details of his pecs and abs finely imprinted on his plastron. He was also getting noticeably taller and broader. Fran's curves were also increasing until her plastron was like a skintight swimsuit. Well, skintight armor, but it was its stiffness didn't hide her body at all. She became slightly curvier than the sisters and it looked like she was a bit taller.
Carl flexed his large arms and said, "I can see why you liked working out, Peter. I feel like I could lift a house."
"You're not that strong so don't even try it," Fran mildly scolded, "I don't want you throwing out your back before I'm done with it."
Peter pretended to not hear that last part and said, "This is so awesome. We're one big turtle family now."
"Turtles forever!" cheered the sisters.
==========
Some time later, Carl and Fran retired to their room. "Think our bed can still hold us?" asked Carl.
"It'll help if we lose some weight," said Fran as she started sliding her shell off. Carl was quick to do so himself and they both looked at each other's bodies. Fran was impressed with how big and muscular her husband had become, especially when compared with his less-physical form before. Carl's eyes eagerly ate up how curvy and buxom Fran was now and he soon found his new rod emerging from its new sheath. Fran looked down at it and was a tiny bit alarmed at how much larger it was now. But that just turned her on more. "Shall we test these bodies out?" she asked huskily.
"Lead the way," said Carl. The two of them climbed onto the bed which creaked quite a bit. It'll probably have to be replaced along with a lot of things to accommodate their new forms. But that could wait until later. Right now, they were too busy testing each other out. Little did their son know that his parents were planning on having a few eggs by spring. And they were certainly going to be putting a lot of work into getting ready. Fran and Carl let out a loud moan as Carl emptied his first batch of turtle seed into his wife. And that was only the beginning of their night.