DISCLAIMER: I do not own Alvin and the Chipmunks or Calvin Klein. The Chipmunks appear as they do in the 1980s show, albeit larger in size.

As he prepared for school one sunny, September morn, Alvin Seville found himself obsessed with an unusual detail. As he stepped out of the bathroom, his gaze fell on a small pile of laundry that had been left atop his bed. Unlike most days, however, this mound consisted only of the two packs of Calvin Klein briefs he had picked up the day before.

With a wide, glowing smile, Alvin dropped his towel and plucked a single pair from the peak. He paused at first, rubbing the soft, white cotton between his thumb and forefinger, admiring its texture. After a moment, the larger digit ran across bright, red elastic and over the neat, white letters that spelled out the iconic brand’s name. Finally, with a contented sigh, the small redhead stepped through the leg holes and pulled the garment into place.

 “A perfect fit,” he beamed, turning to the full-body mirror nearby, “Today is gonna be fun.”

Half an hour passed in the blink of an eye, and soon Alvin had boarded his usual bus to high school. As normal, he and his eldest brother, Simon, sat with their polyamorous partner, Austin Gallows, in the back row. The latter teen was a gray, Scottish Fold cat with black hair, hazel eyes, and an abnormally short stature. To the other boys’ surprise, Alvin was oddly insistent on sitting between them for once. Then, as the bus lurched away from their neighborhood stop, he eyed the pair with his trademark smirk,

“I’ve got a surprise for you two,” he hummed, unfastening his shorts. Simon’s cheeks flushed with color, and he swallowed hard.

“A-Alvin-!” he started, falling short in his protest. Austin was too stunned to speak.

“Feast your eyes,” Alvin smiled, slipping his shorts down to his ankles. Pulling his shirt up a bit, he exposed his Calvins in their entirety. Austin’s pulse quickened as breath caught in his throat.

“A-Are those…?” he stammered. Alvin nodded, biting his lip as the young feline gave his briefs a feel. “I’m so jealous!”

“Admittedly, I too am overcome with enviousness,” Simon added. Alvin smiled and pulled his pals close; their eyes still glued to his midsection.

“I’m glad you guys like ‘em,” he laughed, “Guess I’ll have to get you both a few pairs.”

“That would be awesome, Al,” Austin beamed, “Thanks.”

Alvin gave the smaller boy a squeeze.

“Don’t mention it.”

After an adventurous school day in which Alvin repeatedly teased his partners, the trio finally came to their last class, PE. Dressing out was more interesting than usual, as the rambunctious redhead captured the locker room’s attention with his briefs. Still, the class itself was rather boring, and for a time the singer thought his day would end on a low note.

Finally, the students returned to the locker room, where Alvin was quick to shed his gym clothes and leave them on a bench. After joining most of the other boys in the showers, he returned to a jarring sight: his gym shorts were missing. Panicking, the young superstar turned to his locker and frantically entered its combination. Inside he found only his backpack and the red t-shirt he had worn to school that day. As if on cue, Austin and Simon walked up in towels.

“Everything alright, Al?” the former asked. Alvin shook his head.

“No!” he whined, “Someone stole my shorts! Do you know what that means?”

“We do,” Simon frowned, “Unfortunately, none of our shorts will fit you.”

Alvin sighed dejectedly..

“Well, this will certainly be interesting…”

Surprisingly, the only overlap between reality and Alvin’s expectations was how many students pointed at him in the halls. As he headed for the rear of the school, where the buses lined up, passing students gathered around him in awe. The small teen was repeatedly asked for an explanation, but also received an abundance of praise. Smartphone cameras snapped left and right, and before long he found himself posing for special requests.

At last, Alvin made it to the rear doors, only for two students from the yearbook class to run up and ask him for one final pose. With an emboldened smile, he obliged, pretending to model his comfy, white briefs. One hand was placed on his hip, keeping the hem of his t-shirt just above the waistband. The other hung idly at his side.

“Damn, you’re a natural, Alvin,” the photographer smiled, snapping a few shots. The ravishing redhead blushed; he did feel oddly at home in front of the camera.

“Thanks,” he squeaked. Finally, he and his partners made it outside and onto their usual bus. Naturally, Alvin sat in the middle again, but this time the trio were drawn to their phones.

“Woah, you seeing this, Si?” Austin asked, gawking at his Twitter app. Simon blanched.

“Yeah,” he sputtered, “How on earth is #AlvinsCalvins trending?”

“W-Wait, what?” Alvin sputtered, shocked. He whipped out his phone and, after a few moments, gasped in surprise. “Guys... I’ve got a private message from the official Calvin Klein account!”

“Really?” Simon asked, raising a brow, “What do they want?”

Alvin scrolled through the letter as quickly as he could read it. It was brief but, to his surprise, expressed the brand’s desire to meet with him to discuss some kind of partnership.

“T-They… want to work with me,” the redhead sputtered after a minute. His partners gasped.

“W-Well, you are pretty cute in those briefs,” Austin blushed. Alvin pulled the small feline close.

“Thanks,” he smiled, “You guys think I should do it?”

“Only if you want to,” Simon advised, his cheeks red, “Though I must agree with Austin…”

Alvin responded with his trademark grin.

“Well then, here goes nothing!”

A few weeks later, Alvin found himself arriving at home after his latest modeling job. As the front door closed behind him, the rambunctious redhead smiled and, as had become habit, slipped off his shorts. Tucking them under his arm, he headed upstairs and discarded them- and his socks and shoes- in the bedroom he and Simon shared. With his Calvins on full display, he headed to the game room to join his partners for some afternoon video games.

Alvin smiled as the pair came into view, cuddled together on the room’s large, cloth couch. They were each dressed in a t-shirt and their own Calvin Klein briefs; the free merch part of the redhead’s modeling deal. Simon’s underwear featured a blue waistband while Austin’s were yellow, but both garments matched their wearer’s shirt. Alvin, dressed similarly in red, plopped down between them.

“Hey guys, ready to get thrashed?” he taunted, grabbing a controller. Austin smiled.

“You wish!”

Simon eyed his brother curiously.

“How’d things go at the shoot?”

Alvin struck a seductive pose.

“Great, as always,’ he teased, “Did you guys have fun without me?”

“Yep,” Austin smiled, “And I warn you, we’ve been practicing.”

Alvin laughed and pulled his brief-clad buddies close.

“Good, you’re gonna need it,” he grinned, “Now, let’s smash!”