Mallory sighed and wiped the sweat from her brow as she closed the hatchback of her reliable, blue, S.U.V. She glanced at her watch and felt a satisfied feeling of being done right on time. Which is more than she could say for her travel companions, which should have met her at her house several hours ago.

Mallory had been looking forward to this trip for a while. A week-long getaway to a cabin in the mountains. A time away from work and all the people that annoyed her. Her only company on this trip was a couple: Josh and Rosie. Mallory liked the two. They were cute together and were fun to be around in general. It’s why they were Mallory’s first choice when she realized she would have to split the cost of the cabin, as well as the long drive time, with someone. Though their tardiness was slowly making Mallory more and more annoyed with her choice. She had a good idea what was keeping the two. It was likely the strange quirk in their relationship. She would find out, soon as the couple's small, brown, car began rolling into her drive.

The fact that the car’s back seat was filled with scant bits of luggage emphasized why they were taking Mallory’s S.U.V on this trip. Even with her own bags in there, Mallory was pretty sure her larger vehicle could comfortably hold all their luggage and all three of them, even if Rosie insisted on bringing her extra luggage. Judging by the outfit Rosie was wearing when she eagerly ran out the car, she probably did.

Mallory herself was wearing some comfortable for the road: sweats and a loose t-shirt. Josh was wearing a plain t-shirt and jeans a similarly comfortable outfit. In contrast to the plain clothes of the other two, Rosie's outfit was bright and exuberant. She had on a purple top decorated with cartoon bunnies playing on different video games, and over that was a pink skirtall decorated with cute cosmic fish. Rosie was downright adorable, which only confirmed Mallory’s suspicions.

“Mallory!” Rosie excitedly hugged Mallory as Josh slowly followed over.

“Sorry for the wait,” Josh apologized. “We weren’t quite as packed as I thought we were.”

“Uhh uh,” Mallory said with an accusatory tone. “I know what that means,” she gruffly peeled Rosie off her. “Ok little girl, no since hiding it. I know what that outfit is and what’s under it. Let me see your diaper.” Rosie's face grew flush.

“Daddy,” Rosie whined at Josh.

“I told you she’d notice right away,” Josh said sympathetically. “Go ahead sweetie.” Rosie donned an innocent smile as she raised her skirtall, revealing that the top she was wearing was in fact a onesie. Through Mallory could already see bits of it poking out of the onesie's leg holes, she popped open the onesie’s snaps to undoubtedly confirm that underneath that onesie was a cutely printed adult diaper.

“You really thought I wouldn’t notice?” Mallory gave an accusing look. "Or that I wouldn't expect this?" Rosie looked away ashamed.

“Come on Mallory,” Rosie explained. “It’s a road trip. There’s so many cute things I can do, I can’t resist wearing diapers.”

“Lucky for you I predicted you might want to wear diapers on our trip and I accounted for it,” Mallory said with pride. “Though a case of diapers and baby toys takes up a lot of room.”

“And a car seat,” Rosie said with a slight wince.

“A car seat!?” Mallory shouted back. She looked to Josh for confirmation. He laughed innocently.

“It’s in the trunk,” Josh explained. “You don’t have to take it but …”

“Pleeeeeease,” Rosie cut in with begging. “I’ve been sitting on this thing for so long and I’ve never gotten to use it. It doesn’t even fit safely in my car, but a long road trip, in your big car. It’s the perfect opportunity.”

“All right let’s see it,” Mallory said with reluctance. The group moved over to the car’s trunk and popped it open. Inside, taking up most of the trunk space, was the adult sized car seat in question. It was big and gaudy, like any piece of adult baby gear would be, with a five-point harness and a buckle with a much more secure lock than was probably necessary. “Is this even going to fit?” Mallory questioned.

“It should,” Josh explained. “I'll have to take out the seat and replace it.”

“What?” Mallory said shocked.

“It’s not as bad as it sounds,” Josh said quickly. “I’ve taken our seats out before and it’s pretty easy. I can handle the whole thing.”

“You want me to take out a seat in my car so that Rosie can get off in the back seat the whole trip?”

“Mallory please,” Rosie pleaded.

“I know it’s a lot to ask, and you can say no if you want to,” Josh said hopefully. Mallory looked between the two and their hopeful faces. She had a reasonable prediction that Rosie and Josh would want to engage in their dynamic during the vacation, and she really didn’t have a problem with that. She thought it was cute, even though she didn’t really get it herself, and it would be ultimately harmless for her enjoyment of the vacation. It’s Josh that’d be spending half his vacation changing diapers not her, but he liked doing that. Mallory didn’t know that indulging in this would involve altering her car. Still, even if she didn’t understand it exactly, holding onto this car seat for this long without being able to really use it would be torture, and this was the perfect scenario to use it.

“You’re sure you can put it in without breaking anything?” Mallory asked Josh, Rosie’s face lit up at the implication.

“I’m sure,” Josh assured.

“Well hurry up then, we’re already running late,” Mallory exhaled as Josh got to work.

“Oh, thank you! Thank you! Thank you!” Rosie gleefully squealed.

“Don’t thank me yet little lady,” Mallory was taking out some of her frustration by asserting dominance over Rosie, only because she knew Rosie liked it. “If I’m taking my seat out for this thing, you better be damn sure that if you’re going anywhere in this car it’s going to be in that car seat, and I don’t wanna see you out of diapers for this whole trip. If you are, I’ll have your daddy spank you enough that you won’t enjoy it. Are we clear?”

“Y-y-yes ma’am,” Rosie was absolutely flushed, almost squirming with forbidden delight, and Mallory felt a little less stressed about the whole thing. They both got what they wanted.

“Now snap your onesie up and put your paci in,” Mallory commanded. “I don’t wanna waste any more time.”

“Yes Miss Mallory,” Rosie said with meek obedience. She busied herself doing just that while Mallory went to check on Josh. The sight of her car’s normal seat on the ground next to the car was a bit unnerving, but Mallory had to admit that the replacement car seat looked like an almost natural replacement. Mallory wordlessly grabbed the removed seat and carried it back to her house.

“Ok Rosie,” Josh called out. “Help daddy put our bags in. We don’t wanna keep Mallory waiting any longer than we have to.”

The would-be daddy daughter couple quickly got to work adding their baggage to Mallory’s own while she unlocked her house to store the seat in. By the time she was back out, and had her house resecured, Rosie and Josh had moved their things over and seemingly gotten ready to go. Josh was sitting in the driver’s seat silently agreeing to take the first shift driving.

Mallory wordlessly got into the passenger seat. She couldn’t help a glance into the back seat. Rosie was strapped securely into her car seat. She was gleefully suckling on a pink pacifier. A baby bottle full of water was in one cupholder attached to the arm of the car seat, and a bag of goldfish was in the matching cupholder on the other arm. Rosie was in obvious glee at being stuck in the infantile seat. Mallory had to admit that she did look incredibly cute in her car seat, and seeing the joy in her face made the anxiety of removing her traditional car seat worth it.

“Ready to shove off?” Josh asked. This snapped Mallory out of her trance staring at Rosie. The look on Josh’s face said that he definitely noticed and this caused Mallory to blush.

“Yeah,” Mallory said quietly. “You got the G.P.S. loaded?”

“Yes ma’am,” Josh smiled showing his phone loaded with the address to the cabin.

“Well let’s get going,” Mallory regained confidence. “I needs my vacation.”

“Vacation!” Rosie said excitedly in the back as the S.U.V finally drove off.

Despite the much more juvenile seat one of the passengers was stuck in the drive was pretty much normal. Despite her conditions, Rosie was able to have adult conversation with only a moderate amount of little whine or lisps sneaking in. When she wasn't she was also just as happy being ignored like a child while Mallory and Josh had adult conversation.

Mallory had gotten used to the couple’s dynamic in the time she had known them. She even enjoyed partaking in it to the limited extent that she did. That’s why this whole thing didn’t bother her aside from a nagging anxiety about a missing seat. Even then if her seat was permanently replaced with this adult baby car seat, Mallory wondered if she would even mind that much. Like any good road trip though they eventually had to stop for gas. Josh pulled into a relatively remote gas station and stretched with stiffness.

“Thank god. I’ve been holding it in for an hour,” Mallory said hurriedly moving to get out of the car. Rosie predictably giggled. “At least I’m big enough to use the potty unlike some babys,” Mallory teased. Rosie stuck her tongue out as Josh started to step out as well.

“Let me out! Let me out!” Rosie whined playfully.

“I don’t see any reason too,” Mallory just as playfully egged Rosie on. “You don’t need to go potty, so the only reason you need to be let out of your car seat is if you need a diaper change. Do you need a diaper change little girl? Is your diaper all soggy?” Mallory really layed the teasing on thick.

“Nuh uh,” Rosie petulantly pouted.

“Well let’s check,” Josh said suddenly opening the door next to Rosie’s car seat. He quickly lifted her skirt and opened the onesie even with the strap of the five-point harness in the way. “Oh, you’re soggy all right.”

“Daddy,” Rosie whined with embarrassment.

“I knew you would be,” Mallory said indignantly.

“Not enough to need a diaper change yet though,” Josh said with a feigned unimpressed reaction.

“What?” Rosie was aghast. At this point Mallory had run off to the gas station itself as the need to go had gotten severe.

“You can still get out and stretch your legs if you want to,” Josh started to offer. Rosie's face lit up at the offer. “It’ll be on your baby leash though.” Rosie's face shifted from joy to a more flushed sense of joy. She looked around from her car seat to see how many people were around, and they were just remote enough to maybe get away with that. There was always the chance that someone would look over and see her, a grown woman, on a baby leash and make their own conclusions. Josh gave a playful smirk at Rosie's sudden blush. “I made sure it was left out just in case you wanted to.” Josh continued. Rosie’s emotions were a contradiction. Nervous yet also excited for the opportunity.

“Ok, but only for a little bit,” Rosie whispered in an adult tone.

Mallory had just returned from the gas station, opening the bag of chips she had bought from inside when she heard giggling from the other side of the car. When she peeked around the other side, she saw Rosie and Josh both nervously giggling, Rosie bouncing around happily with a pink leather harness around her chest and a leash going from it to Josh’s hand. Somewhat ironically, the two were so nervous about moving from behind the car that the leash was practically useless and unnecessary.

“Really you two?” Mallory sighed in annoyance. “What if someone sees you?”

“What if they do?” Rosie giggled excitedly.

“Don’t worry Mallory,” Josh was more reassuring. “I made sure no one was around, and even if they were, it’s not like it’s illegal to walk my girlfriend on a leash.”

“I’m sure someone could come up with some law that you’re breaking,” Mallory fired back half-heartedly. “You better wrap it up anyway because I’m not holding her leash while you take a piss.”

“Awwww,” Rosie sighed sadly.

“You could wear it into the store if you want,” Josh offered. Rosie's disposition got immediately more anxious. “Thought so,” Josh said with a grin. “Let’s get you strapped back in then.” Rosie was back into her car seat by the time Mallory had situated herself in the driver’s seat ready to take her turn at the wheel. She glanced into the rear-view mirror at Rosie in the back seat still wearing a shy grin on her face.

“That was reckless you know,” Mallory said with a lack of conviction.

“I’m sorry,” Rosie said with some regret. “It’s just something we’ve always wanted to do you know.”

“Did you have fun?” Mallory asked with a sly look on her face.

“Yeah,” Rosie donned a playful blush.

“Good,” Mallory couldn’t help but smile. “So, you’ve got your stuck in a car seat fantasy, and your walked on a leash fantasy. What’s left?”

“We still haven’t done a diaper change in the back seat by the side of the road,” Rosie said thoughtfully.

“Hand me your bottle then,” Mallory reached back for the container. It was predictable empty; Rosie had been drinking from it since they left. “If you’re going to cross that one off your list then you need to get to making that diaper soggier,” Mallory reached into a cooler used for road snacks and drinks that had been placed in the seat next to Rosie and grabbed a bottle of water. She started filling the bottle back up as she talked. “We’re really not that far from the cabin so you don’t have that much road left.” She reached back to hand Rosie the now full bottle and Rosie’s face smiled with determination. Not long after that Josh returned, hopping into the passenger seat, and the car got on the road again.

It wasn’t that much longer that Rosie would get her final fantasy crossed off her list. Really the group was close enough to their destination that it was far more effective to just wait until they arrived to change Rosie’s now sodden diaper, but that would rob her of the experience.

So, only about 20 miles away from the cabin, Mallory’s S.U.V. was pulled off on one side of the road. Mallory was leaning against the car on one side, watching for any other cars that might want to stop to help them and hopefully dissuade them from investigating. For, on the other side of the car, Josh and Rosie were navigating a back seat diaper change with some difficulty if the noises were anything to go by. They had been at it a while before Josh finally came around to signal he was done and Rosie was strapped back into her car seat. Mallory got in the car and they wordlessly got back on the road. Mallory sighed with content knowing they were almost to their vacation destination.

“Hey Mallory,” Rosie said suddenly. Mallory looked into the back seat. “Thanks for letting us have our fun.” Mallory couldn’t help but smile.

“You’re welcome little Rosie,” Mallory’s smile grew and she turned back around.