Gina’s heart fluttered with a mix of excitement and nerves as she woke to the sunlight streaming through her bedroom window. She stretched under the covers, her toned legs shifting against the sheets, and smiled at the thought of the day ahead. Running with Amy sounded fun, even if she wasn’t sure she could keep up. Her body felt ready, though—flat stomach taut from occasional walks, D-cup breasts pressing against her nightshirt, and that bubble butt that always drew stares she pretended not to notice. She was shy about it all, but today felt like an adventure.

After a quick shower, the warm water cascading over her smooth skin, Gina dried off and rummaged through her drawer. Her usual sweatshirt and basketball shorts would have to do; she didn’t own much workout gear. The fabric felt loose and comfortable as she pulled it on, but a knock at the door interrupted her thoughts. ‘That must be Amy,’ she thought, her cheeks warming already.

“Good morning, Amy!” Gina said, opening the door with a grin that betrayed her inner jitters.

“Good morning!” Amy replied, her eyes scanning Gina up and down with a teasing glint. Amy looked put-together effortlessly in her fitted tank top and leggings, her confident posture making Gina feel even smaller. “Is this what you’re wearing for our run?”

“Yeah, is that okay?” Gina asked, tugging at the hem of her sweatshirt self-consciously.

Amy shook her head, a playful scold in her voice. “Gina! It’s like 90 degrees out! This will never do, but lucky for you, I brought an extra set of clothes that no longer fit me. Now, change into these.”

She tossed a white sports bra and a pair of white spandex shorts onto the bed. Gina caught them, feeling the stretchy material between her fingers. “Oh, thank you so much!” she said, already peeling off her sweatshirt without a second thought.

Her breasts bounced free as she stripped down to her underwear and sneakers, the room’s open window letting in a breeze that brushed her bare skin. She didn’t notice the way the curtains fluttered, or how exposed she suddenly felt, her flat stomach and the curve of her hips on full display. Gina hooked her thumbs into her panties next, sliding them down her toned legs. The air felt cool against her bare pussy, a faint tingle of vulnerability making her pause, but Amy’s giggle pushed her forward.

“Those shorts aren’t meant to be worn with underwear, silly,” Amy said, her tone light and encouraging. “Neither is the sports bra.”

“Oh, OK,” Gina nodded, her dumb trust kicking in as she stepped out of the last scrap of fabric.

Now completely nude except for her sneakers, she felt a flush creep up her neck, but the excitement of the run—and pleasing her friend—overrode it. She bent slightly to pull on the spandex shorts, the material clinging to her skin immediately. Her bubble butt strained against the tight fabric, the shorts riding up between her cheeks as she tugged them higher. It was a struggle; the spandex stretched taut over her ass, hugging every curve like a second skin.

“Need a hand?” Amy asked, stepping closer, her eyes lingering on Gina’s exposed body.

Gina straightened, the shorts now wedged uncomfortably but snugly in place. “I think I got it,” she murmured, though her voice wavered.

Next came the sports bra, which proved even trickier. Gina pulled it over her head, her breasts spilling against the too-small cups. The fabric barely contained her D-cup tits, cleavage bulging from the top and sides, the undercurve peeking out below. Her nipples hardened slightly against the thin material from the friction, a secret sensation that made her shift her weight.

Amy circled her, nodding approvingly. “Do they fit well?”

“They feel a little tight,” Gina admitted, adjusting the bra and feeling the spandex dig into her hips.

“Don’t worry, that’s how they’re supposed to feel,” Amy assured, her hand brushing Gina’s arm in a way that sent a warm spark through her. “OK, let’s do some stretching before we get into the run. Now bend down and touch your toes.”

Gina complied, bending at the waist, her legs straight and toned muscles flexing. The position pulled the shorts even tighter, the fabric outlining her pussy lips through the thin white material. She felt the air on her mostly bare ass cheeks, the breeze from the window teasing her exposed skin. Her heart raced—not just from the stretch, but from the odd thrill of it all, the way Amy’s gaze burned into her. ‘Was this normal?’ Gina wondered, her gullible mind brushing off the doubt.

“Good, good,” Amy murmured, her voice closer now. She placed a hand on Gina’s lower back, guiding her deeper into the bend. “Let me just fix your shorts a bit.”

Her fingers hooked into the waistband, yanking upward with a firm tug. The spandex snapped higher, wedging deep between Gina’s ass cheeks like a thong, the front panel pulling tight against her mound. Gina gasped, the sudden pressure rubbing right against her clit, a jolt of unexpected heat flooding her core.

“Amy, that feels ... really tight,” Gina said, her voice breathy as she tried to hold the stretch. Her cheeks burned with embarrassment, but there was something else too—a curious warmth building low in her belly, her body responding to the exposure and the touch.

“Perfect form,” Amy replied, her hand lingering on Gina’s hip, thumb tracing the edge of the wedged fabric.

She stood just behind, watching the way Gina’s bubble butt flexed, the white spandex translucent in the sunlight, hinting at the smooth skin beneath. Amy’s breath quickened, enjoying the view of her shy friend’s unwitting display, the open window framing it all like a private show for anyone glancing by.

Gina straightened slowly, her skin tingling everywhere the tight clothes touched. She glanced at the window, finally noticing it was wide open, but Amy’s encouraging smile made her push the worry aside.

“Ready to run?” Amy asked, her eyes sparkling with mischief.

Gina nodded, her pulse thrumming with a mix of nerves and that strange, budding excitement. As they stepped toward the door, the spandex shifted with every movement, a constant reminder of how little separated her from the world outside.

Amy paused at the door, her hand on the knob, turning to Gina with a sly smile. “You know, the apartment complex track might be too crowded today. How about we head to the nearby park instead? It’s got open paths, fresh air, and way more space to really stretch our legs. Plus, it’s just a short walk from here.”

Gina’s stomach twisted at the idea. The park meant people—joggers, families, dog walkers—all out in the open, basking in the bright sun. In these clothes? The spandex shorts were already riding up with every step, the thin strip buried between her ass cheeks, leaving her bubble butt almost fully exposed. The sports bra squeezed her D-cup breasts, the fabric so taut it outlined her hardening nipples against the cool air from the hallway. She glanced down at herself, cheeks flushing hot.

“The park? But ... I’m not sure. What if it’s too hot? Or ... people see me like this?” Gina asked.

Amy stepped closer, her confident gaze locking onto Gina’s nervous eyes. She reached out, lightly tugging at the edge of the wedged shorts, making Gina squirm as the material shifted against her sensitive skin.

“Come on, Gina. That’s the fun part. You look incredible—sexy as hell in this outfit. Trust me, a little exposure will make the run even more exciting. It’ll get your blood pumping.” Her voice dropped to a teasing whisper, fingers brushing Gina’s hip. ‘Besides, I want to see you out there, all flushed and free.’

Gina bit her lip, her gullible nature warring with the shy knot in her chest. Amy’s words sent a warm flutter through her, mixing embarrassment with something more profound—a curious thrill at the thought of eyes on her body. Her pussy tingled faintly from the constant rub of the spandex, already dampening the fabric between her thighs.

“Okay ... if you think it’s fine,” she murmured, her voice small but laced with nervous excitement.

She followed Amy out the door, the hallway’s air conditioning raising goosebumps on her bare midriff and the undersides of her breasts.

The short walk to the park felt endless. Gina kept her arms crossed loosely over her chest, trying to shield her spilling cleavage, but it only pushed her tits up higher, the sports bra straining. Her toned legs moved quickly, the sneakers padding on the sidewalk, but each stride made the thong-like shorts dig deeper, the front panel pressing right against her clit.

She could feel the sun warming her exposed ass cheeks, the breeze teasing the bare skin where the fabric didn’t cover. A few neighbors glanced out their windows or passed by on the street, their eyes widening at the sight of her nearly nude form. One guy on a bike slowed down, staring openly at her bubble butt as she walked, his gaze making her heart pound.

By the time they reached the park entrance, Gina’s face burned crimson. The open green space bustled with activity—runners on the paths, people picnicking under trees, a group of guys playing frisbee nearby. Amy led the way confidently, her own outfit modest in comparison, drawing Gina deeper into the exposure.

“See? Perfect spot,” Amy said, gesturing to a shaded path winding through the grass. “Let’s start with a jog. Keep up if you can.”

They set off at a slow pace, Gina’s breath coming quick, not just from the effort. Almost immediately, heads turned. A woman pushing a stroller did a double-take, her eyes flicking to Gina’s barely-contained breasts bouncing with each step, the sports bra doing little to hide the jiggle. Two joggers coming the opposite way slowed, one whispering to the other as they ogled Gina’s ass, the white spandex translucent with sweat already forming, hinting at the curve of her pussy lips beneath.

Gina’s skin prickled under their stares, a wave of humiliation crashing over her, but it tangled with a forbidden heat low in her belly. Her nipples ached against the fabric, fully erect now, and she felt a slick warmth building between her legs, the tight shorts rubbing insistently.

Amy glanced back, her eyes gleaming with playful dominance. She matched Gina’s pace, staying close enough to watch every flush on her friend’s face. “God, Gina, you have no idea how hot you look right now. That ass of yours in those shorts? It’s like it’s begging for attention. And your tits—spilling out like that, nipples poking through. Everyone’s staring because they can’t help it.” She leaned in during a brief slowdown, her breath hot on Gina’s ear. “Does it turn you on? Feeling their eyes on your bare skin, knowing how exposed you are?”

Gina’s cheeks flamed, but she couldn’t deny the rush. The embarrassment made her want to hide, yet Amy’s teasing words stoked the arousal, her body betraying her with every bounce and rub. “Amy, stop ... It’s so embarrassing,” she whispered, though her voice held a breathy edge, her flat stomach tightening as another group of college guys whistled softly from a bench, their gazes locked on her wedged ass.

One called out, “Looking good, ladies!” but his eyes stayed on Gina, making her pussy clench involuntarily.

“Embarrassing? Nah, it’s empowering,” Amy countered, her hand grazing Gina’s lower back, fingers dipping just under the waistband to adjust the thong higher. The tug sent a spark straight to Gina’s core, her clit throbbing against the pressure. “Embrace it. Run faster—let them see how your body moves, all toned and sexy. You’re turning heads left and right, and I love watching you squirm.” Amy’s touch lingered, possessive and encouraging, as they picked up speed along the path.

Gina’s mind spun with conflicting emotions—the shy girl in her screaming to cover up, but the ditzy thrill of Amy’s approval and the strangers’ stares pulling her deeper into the heat. Sweat trickled down her cleavage, soaking the sports bra and making it cling even tighter, her D-cup breasts heaving with each breath. The park’s paths curved ahead, more people visible in the distance, her arousal building steadily despite—or because of—the exposure.

The run stretched on longer than Gina expected, her body slick with sweat under the relentless sun. Amy pushed the pace, weaving through the park’s paths where more eyes caught sight of her. A cluster of older men on a bench, their gazes lingering on the way her bubble butt flexed with each stride, the white spandex now sheer and clinging to the sweat-dampened curves of her ass cheeks.

Gina’s heart raced, not just from the exertion but from the constant thrill of exposure, her pussy lips swollen and rubbing against the tight fabric, sending jolts of unwanted pleasure up her spine. By the time Amy slowed to a walk near the park’s edge, Gina’s legs trembled, her breath coming in short gasps, D-cup breasts rising and falling, nipples stiff and visible through the soaked sports bra.

“Whew, that was intense,” Amy said, wiping her forehead with a grin. “Come on, let’s head back to my place. You look like you could use some water.”

She looped her arm through Gina’s, guiding her out of the park and along the familiar streets toward the apartment complex. The walk back felt even more exposing now, with Gina’s clothes plastered to her skin, the thong wedged so deep it outlined every intimate fold. A car slowed as it passed, the driver craning his neck for a better look at her glistening ass, and Gina’s cheeks burned, a fresh wave of embarrassment flooding her even as her core tightened with that confusing heat.

They reached Amy’s door, both panting and flushed. Amy pushed it open, the cool air from inside rushing out like a balm against Gina’s overheated skin. “Let’s grab some water and catch our breath,” Amy sighed, her eyes flicking down to Gina’s body, lingering on the way the sweat traced paths over her flat stomach and down to the wedged shorts that barely covered anything.

Gina stepped inside, grateful for the momentary privacy, though the apartment’s open layout meant little cover. Her thighs stuck together from the moisture building between them, and she shifted uncomfortably, feeling the spandex pull taut against her sensitive clit.

“Hi, girls!” Dylan called from the living room couch, where he sat with a video game controller in hand.

His eyes widened as he took in Gina, gaze dropping immediately to her sweat-glossed bubble butt, the cheeks entirely on display as the shorts rode up like a permanent thong. He was Amy’s younger brother, awkward and sweet, with a not-so-secret crush on Gina that made his cheeks pink up now. He tried to play it cool, but his stare lingered, tracing the sheen of sweat that made her skin glow, the way her ass jiggled slightly as she moved.