It was the most memorable and erotic public experience I ever had. I was thirteen and things were sprouting up all over, pubic hair, height, shoe-size, erections. Lots and lots of daily, embarrassing, spontaneous and extremely public erections I was constantly hiding from view with jackets, shirt tails, books, whatever was handy whenever I couldn't get to a restroom or somewhere equally private to stroke my poor throbbing penis to a satisfying and ultimately deflating orgasm!!
All it would take was a glimpse of stocking-top, pantyline or bra-strap and my penis would twitch and grow inside my underpants till it pushed obscenely against my trousers. If I was sitting, it was fine, but having to stand or walk with my penis throbbing hotly in tight pants always made me nervous and terribly, terribly aroused. Movement caused friction and friction produced a light but steady flow of pre-cum and pre-cum stains. It was all I could do to get home before something awful happened, but I always did.
Till one day...
I was on a bus, going home from Lacrosse practice at my junior high school. It was crowded, standing room only. I held on to a pole in the crush and swayed with the rest of the passengers as the bus made it's way through the streets. Standing just ahead of me was a woman of about 45 years old. She wasn't particularly tall, but seemed kind of imposing just the same. She was dressed in a light, pink summer dress, white handbag and gloves and wore sunglasses. The dress was sleeveless and standing behind her as I was, I could see past her armpit and along the side of one of her bosoms, held tightly in a white lace bra, and suddenly, my penis was hard and standing straight out against the front of my slacks.
'Please don't turn around... please don't turn around... please don't turn around,' I silently prayed over and over till suddenly, the bus lurched to a stop and I was shoved from behind by a mass of bodies right into the lady's back, my boner pushing up against her bottom. I managed to apologize, but it was hardly necessary, she knew as well as I that it couldn't be helped.
She said nothing, didn't turn round, wouldn't even acknowledge me, but just stared straight ahead and continued holding on to the strap above our heads. I tried to slowly, carefully disengage my groin from her buttocks, but at that moment the bus lurched forward again, sending her against me as the momentum shifted and I felt the head of my penis slide across her buttocks to land directly in between where it lodged itself.
The feeling was more intensely erotic than anything that had ever happened to me in my young life. I began to panic. The way the bus swayed and the bodies behind me pressed, the friction of my bulging penis sliding up and down in her crack was beginning to create a problem; a dark stain had appeared where my pre-cum had wet through my underpants and if the movements kept up much longer, I was in danger of having an orgasm right there in my pants.
I held my breath, bit my lip and tried doing my multiplication tables, but nothing worked. I heard the lady gasp and thought she was about to scream or turn and slap me in the face or have me arrested, but instead, she did something I will never forget. Without turning around, she began moving her hips in such a way that she was literally masturbating my penis with her buttocks.
I was holding my breath, listening to hers come in shakey sighs and little whimpers. I held on for dear life, subtly humping against her tush. Looking over her shoulder I could see she was pressed against a pole in front, the cold steel pushed hard against her mound, sliding hard between her labia underneath her dress and panties.
'Keep going, child' she hissed under her breath. 'Keep going... keep going... I'm almost there. Keep rubbing your penis against me.' As I felt my orgasm starting, my knees were shaking so badly I grabbed her hips with both hands to steady myself. Her legs stiffened and tightened against the pole as she squeezed her buttocks, trapping my suddenly erupting penis between, climaxing into her panties as I felt my hot, sticky, seed filling my underpants in long, exquisite spurts.