Calvin handed Dave a pair of large, white briefs, larger than anything Dave would wear. Confused, Dave takes the briefs, not wanting to offend the strange employee, and stepped into the changing room.
Dave began undressing, muttering to himself about the strangeness of the whole situation. First Dave removed his jacket and shirt, exposing his lanky and bare torso. He then takes off his shoes and slips off his pants. He put his discarded clothes on a nearby bench and stood in his socks and boxers in front of the wall mirror, hands on his hip, examining himself.
"Sheesh," he said to himself under his breath, "I should start working out." He then tugged on his boxer briefs' waist band, put them on top of his other clothes, and reached for the briefs Calvin had handed him.
He put his scrawny legs through the too-large leg holes and pulled them up to his waist. he let go of the waistband and the briefs slid down to his hips, the moment the waistband touched his skin, Dave felt a shiver run down his spine. Assuming it was simply due to the store's chilly air conditioning, he brushed it off and pulled the sagging briefs back up to his waist. He looked up and smirked at how ridiculous he looked, wearing the huge briefs, having to hold them up to keep them from slipping. He turned around to get ready to change back into his own clothes, letting go of the briefs when his smirk disappeared. The briefs weren't slipping off like before.
He looked down to try and see was wrong and staggered back out of sheer shock. Instead of his flat and pasty chest, he saw a small beer belly protruding from under a pair of muscular pecs, all covered in a light dusting of sandy blond hair. He reached towards his new belly, realizing that his hands were unfamiliar as well; he brought them up to his face to get a better look. His dainty hands had been replaced by a pair of meaty and calloused paws. His palms were rough and his fingers were square, when he flipped them to look at their backs he discovered small hairs dusting his knuckles and the backs of his new hands. Dave's gaze went up his wrists and he stared at his sinewy forearms covered in thick blond hairs, up to his incredibly large biceps, and back down to his solid chest. He grabbed his belly and gave it a squeeze.
"I'm not dreaming," he muttered, "whoa. Is that- Is that MY voice?" he asked out loud as he held a meaty hand to his throat, feeling the bristly stubble that now seemed to cover his chin. he turned around to face the mirror again and gawked at his new reflection.
Staring back at him was a man in either his late thirties or early forties. His face, much like his hands, was rugged, with bushy eyebrows, navy blue eyes, a prominent nose, and thin lips framed by a bristly goatee. the top of his head was home to a mop of shoulder-length dirty blond hair that framed his new features. Below the small protruding belly, he could see a solid, round ass, and a noticeable bulge pushing on the now perfectly-fitting briefs. His new legs were toned, muscular and covered in the same thick hairs that dusted his forearms, while his large feet were stretching his crew socks to their limit.
His old clothes obviously would no longer fit him. He staggered over to the door, unused to his new weight and height and peered outside the door where Calvin was expectantly standing.
"Calvin, I uh, think I'm gonna need new clothes," he whispered, cringing at the raspy baritone that made his whole chest reverberate.
"Of course!" Calvin replied unfazed before handing Dave a white undershirt, canvas short-sleeve button up, a pair of cargo shorts, and size 13 flip-flops.
Dave baffled by Calvin's lack of reaction to his sudden change.