Crossing Gender Lines (Chapter 1)

Chapter 1: Sisterly Encouragement

I couldn’t help myself. I’d always been fascinated with women’s underwear. The idea that they caress a woman’s most intimate area has always turned me on. I knew that it was weird, even borderline fetishistic, but I just couldn’t ignore the thrill it brought me. I was ready to turn it up another notch.

I crept into my sister’s room feeling like a criminal. The late afternoon sunlight shone through her bedroom windows as I checked each dresser drawer until I found what I was searching for. Silky, soft panties, bras, and other lingerie pieces greeted me with an alluring charm that was impossible to resist. I picked up a pair of her satin bikini panties and held them to my nose, inhaling the scent of clean women’s underwear.

I couldn’t explain why, but the scent of her clean panties made me feel closer to her, and for some reason, more aroused. I looked around her bedroom and saw a picture of her and me on the wall. I felt slightly guilty for breaking her trust, but the intense lust pushed me beyond logic and rationale.

My dick was rock hard, sticking out in front of me while my sensitive nipples ached. I had never gone so far before. I had plenty of intimate women’s clothing, but I had bought all of that online, at department stores, and even thrift stores myself. I had never gotten my hands on panties actually owned by a woman before.

I set the stretchy black satin garment on her dresser and pulled off my t-shirt, now standing completely naked in my little sister’s room. I rubbed and pinched my stiff nipples, letting out a quiet groan as my cock throbbed.

I stepped into her panties and gasped as the soft, smooth fabric embraced my ass, cradled my balls, and hugged my rock-hard cock. The sensations seemed more intense than when I wore my own panties, and I imagine it was because they belonged to my sister this time. The feeling of the soft fabric pinning my erection against my body made my head spin.

I couldn’t believe how aroused I was. I pulled a pink sports bra out of the drawer, examining it closely before pulling it over my head and maneuvering it into place. The tight bra hugged my upper chest and pressed against my hard nipples. I took a deep breath and let it out slowly, staring at my reflection in the full-length mirror on the back of my sister’s closet door.

I had never really looked at myself looking so feminine before. I turned to the side, looking at my plump curves, my soft belly, my big round ass squeezed by her shiny panties, and my breasts small but noticeable due to my weight. I really wished I had Stacy’s big breasts just to know what it felt like.

I examined my reflection in the mirror and sighed. I had to control myself, but I wanted more. I found one of her satin bras and wondered what it would look like on me. The cups would be very empty, used to housing her enormous breasts.

I would have given anything to have her body and her assets. My younger sister was a full-figured, curvy young woman, and I admired her body in so many ways. I envied her heavy breasts, her wide hips, her thick thighs, and her beautiful face. I wanted to be her, I wanted to know what it would be like to be in her body, if only for a day.

I sighed again, letting my hands trace their way around my own curves. I knew it was my ass that fueled my desire, as it was the only feminine shape I had to my own body. I was overly fascinated with my own backside. It was big, round, and shaped like a woman’s, that was for sure.

I took notice of the way her panties hugged my crotch tightly, squeezing my erection. My eyes glanced at the clock on her bedside table. It wouldn’t be too long until she’d be back from hanging out with her friends, but I felt like I had plenty of time to enjoy myself in her room.

I wanted to know how it felt to have real breasts, big, heavy breasts like my sister, and I’d tried to simulate the feeling with padding and even water balloons inside my own bras before. But I knew it was nothing like the real thing.

I looked at myself once again, running my hands over my body, feeling the soft fabrics over my skin. I reached down to squeeze against my erection through my sister’s panties, breathing in deeply as I did. I slowly began to rub myself through the front of her panties, my cock head poking its way out just enough for me to feel it along the elastic of the panties.

I closed my eyes, once again imagining myself with a big, bountiful chest, my hands cupping them as I felt the weight of a woman’s curves as my own. My breathing got heavier and heavier. I started to moan and whimper softly with pleasure. I rubbed my hard nipples through the soft cups of Stacy’s bra, causing shivers to run down my spine. My hand gripped my dick tight as I squeezed even harder, getting carried away in my fantasy.

I tried even harder to imagine myself with breasts like Stacy’s. Two enormous, round mounds that filled my hands perfectly. I imagine myself squeezing them, kneading them, playing with my hard nipples and feeling their weight and softness.

I started to rub my nipples and my pulsing cock faster. My moans became louder and deeper as the image in my mind became clearer and more vivid. I could feel the satin sliding against my ass as I moved my hips back and forth in front of the mirror.

My cock was profusely leaking pre-cum. I reached down to grab one of Stacy’s vibrators, hidden away in her underwear drawer. I slipped it into my soaked panties, pressing it against the base of my needy cock. I gripped the mirror frame tight, my knuckles turning white as I watched myself in the mirror. I was a mess of moans and gasps as I felt the vibrations on my dick.

My cock was throbbing, begging for release. I closed my eyes and pictured myself as a woman, my delicate nipples pressed against the fabric of the bra as I rubbed my pussy.

I pulled the vibrator out of my panties and positioned it directly on the head of my rock-hard dick. The vibrations coursed through my body like lighting, sending waves of pleasure pulsating through my nerves. I moaned loudly as the pressure built in my balls, every muscle in my body tensing up tightly as my climax approached.

My hand shook as I pushed the vibrator harder against my swollen head. I felt my cock twitch and heard a gasp behind me.

My eyes snapped open, and I saw Stacy standing in her bedroom doorway, frozen in shock. Her mouth hung open, and her beautiful blue eyes were wide with surprise. Her stare bore into my soul like a hot poker, and I swear I could feel the heat of it against my skin.

She couldn’t tear her eyes away from what she had discovered. Her gaze swept up and down, taking in every inch of me with her gorgeous eyes.

“What the fuck, Nick? What perverted shit is this?!” She exclaimed, unable to hide her shock.

I froze, the vibrator still pressed against my straining cock. I felt my heart race, a mix of panic and embarrassment flooding my senses. “Stacy, I…” I stammered, trying to come up with some excuse, hoping that I would wake up from this nightmare.

“You dumbass!” she exclaimed, her hands flying to her hips, “What on earth are you doing wearing my underwear? And are you really using my vibrator like that?” She asked, her eyes narrowing, a bewildered half-smile appearing on her lips.

I was frozen, speechless, and I just couldn’t believe it. My little sister saw me, and she wasn’t calling the cops or screaming bloody murder. On a strange impulse, I took a step towards her, the vibrator still pressed tight against my leaking cockhead. A shiver shot up my spine as the vibrations moved down the shaft, firing through my balls. She tilted her head and shifted slightly, looking me up and down with curiosity and wonder in her eyes.

Her gaze lingered on my soft, plump figure, as well as on the tight sports bra and shiny panties I had on, her own underwear clinging to my ass. “Nick, I know you like to dress up, but I never thought you’d put on my clothes. How many times have you done this before?” she asked, a soft smile starting to form on her lips.

I swallowed hard, my heart pounding as I looked at her, still holding her vibrator against my throbbing cock head, leaking copious amounts of precum down and saturating the front of her delicate panties.