“You’re such a good girl, aren’t you?”

I feel her fingers stroke my hair, and I am instantly awake. I stare into her hypnotic green eyes.

“Yes, Miss,” I whisper.

“You’ll do anything I say, won’t you?”

Oh god, here it is. She’s going to do something extra humiliating.

“You know I will, Miss.”

“Good girl.”

She climbs off the bed and goes to my wardrobe. I lie there and watch her. I glance at the clock. 7.48am. It’s early, but I guess she has to go to work soon. I love these weekday nights when she stays over. Despite her being almost twice my age, she still looks so good. She rifles through my tops, selecting then discarding one after another before finally choosing an old pink tee shirt with a faded grey logo that’s been at the back of my drawer for years and which is probably a size too small for me.

She throws it at me and tells me to put it on. Since she didn’t choose a bra, I figure I’m going braless today. As I suspected, the top is very tight. My nipples poke through. You can see the outline of the piercings she made me get for my birthday.

“Catch!” I reach out and grab the panties she throws at me. They're my favourites. I love the multicoloured polka dots on them, and I remember how she danced her fingers over them the first night she took me home.

I slip my legs into them and pull them up. By this time, she’s handed me my pink and black tartan skater skirt, and I quickly put that on as well.

She rummages in my sock drawer and finally produces a pair of pale grey over-the-knee socks.

“There you go. You’ll look perfect.”

“Thank you, Miss.” I nod shyly then finish getting dressed for her, pulling on my canvas pumps.

She gets dressed too, and we leave my room and head out. Her car is parked on the road outside my flat and without any discussion, she presses her keyfob and unlocks the doors. I climb into the passenger seat, settling into the cool leather seat while she moves around to the driver's side.

Once inside, she opens the glove compartment and hands me a bottle of water while taking one for herself. I open and take a long drink before asking where we are going.

“It’s a surprise.”

The grin she gives me tells me all I need to know, and I squeeze my thighs together while possibilities run through my head.

We drive through the quiet streets and out into the countryside. It’s early on a beautiful spring morning and it feels like we are the only people awake.

“Drink up,” she tells me when she notices me holding onto the water bottle. “You need to stay hydrated.”

I obediently swallow the rest of the bottle and place it in the little bin tidy she has between the seats. I relax and watch her drive. She exudes confidence in everything she does. It’s as if she expects the other cars to get out of her way. It was like that when we met. I can’t recall there being much discussion. It was as if she assumed I was submissive and would do as she said. I don’t recall ever telling her outright that humiliation was a kink, but somehow, she guessed. Every so often she somehow manufactures a scenario where I am publicly humiliated.

My thoughts are interrupted by her handing me another bottle of water. “Drink up.”

I am about to protest that I’ve only just finished the last one when the look in her eye tells me not to argue. I dutifully uncap the bottle and drain it in three or four long gulps.

“Good girl,” she coos, and I feel a blush of pride warm my cheeks. It’s hard to explain, but those two words just do it for me.

We’ve driven for about half an hour by this stage and have left our university town far behind. It feels naughty heading out for the day when she has work and I have lectures to go to, but I don’t care, as I get to spend the time with her.

“Here, drink this.”

I glance at yet another bottle of water and then at her. Her face is inscrutable, but it dawns on me what is coming. “Yes, Miss,” I mutter and snatch the bottle. I drink it quickly. She has done this before. Filled me up with water and then refused to let me go to the toilet. This time will be worse. The thought of peeing in her car, of peeing over the expensive leather seats makes me feel flush. Oh, god, the smell of my pee in her car would be so gross. She would kill me. Immediately, my bladder, as if awoken by thoughts of peeing, protests that it is full and needs to go to the toilet.

I look over at her. She has a smirk on her face. She knows that I know. The thought that she is going to drive around the countryside until I lose control has me starting to come out in a cold sweat.

She takes the exit off the motorway, and I glance at the car clock as we enter the suburbs of the next big town from us. It’s almost 8:30am, and we will start to hit the rush hour traffic soon. I remember how she bundled me out of bed and into her car without letting me go for a pee when we got up. A full night’s sleep since last going to the toilet plus three bottles of water is making my bladder protest more with every bump in the road that we drive over.

I grip the door handle. My knuckles go white. I try to concentrate on anything else. Anything to distract my mind from my overfull bladder and the feeling of the leather against the backs of my thighs.

Maybe she doesn’t want me to pee in her car. In fact, I’m sure she doesn’t. I decide to ask.

“Miss, I need to go to the toilet.”

She gives a nod and mutters a "uh huh" but carries on driving. We go past a service station, and I try again, asking her to stop so I can go to the toilet. Again, I get the briefest of acknowledgements that she has heard me, but she carries on.

Finally, we pull up on a street, parking not too far from a bus stop. There are seven or eight people waiting there. Mainly office workers in suits and a couple of students by the look of their clothes. She turns off the engine and sits staring straight ahead.

I squirm; my bladder is now making very strong representations, and I am having to squeeze my pelvic floor muscles to keep it together. I try one last time. “Please, Miss.”

“I know. You really need to go.” She turns and looks at me. “Ok then. Get out of the car and walk over there to the bus stop.” She indicates the group of people across the road. “Go and stand next to that girl in the navy suit holding the coffee cup.” She pauses. “And then pee. Just stand there and let it all run out of you.”

She smiles at the shocked expression on my face.

“I’ll wait here for you. Off you go then. Be quick before the bus comes and you pee in front of a double-decker full of onlookers.”

I blush beetroot red.

“Or you can say no, and we can drive home again.”

I know my bladder will never hold out until we get home again and the thought of peeing in her car forces me to open the door. She doesn’t look at me. She just stares ahead, watching the group of people waiting for the bus.

I step out of the car and cross the road as quickly as I can, aware that moving too fast will cause me to pee too early. I join the crowd of people. I stand next to the woman in the navy suit who smiles a good morning. I inhale the smell of her freshly washed hair. The pain in my bladder is intense. I take a deep breath and relax.

I have to stifle a moan as I finally let my pee flow. I feel it filling my panties, a warmth spreading around my crotch. And then there is the sound. My panties are saturated, and now the pee drips between my legs, drumming on the pavement with a sound that seems amplified. I can feel some of the pee splatter against my thighs. I daren’t look down but am pretty sure my pale grey over-the-knee socks area also showing darker stains.

Then the smell hits me. I see the woman in the navy suit turn to look. Her attractive face curls into a sneer as she glances down and sees the puddle of my piss splashing over my shoes.

“Oh my fucking god, you dirty bitch!” Her cry causes others to look round, and soon everyone is shuffling out of the way as I stand, the stream of piss still flowing from my overfull bladder and splashing on the ground.

I hear a camera phone click. My cheeks flush scarlet. The stench of urine is unmistakable, and I will the flow to the end.

I hear the crowd muttering, saying how disgusting I am and how it shouldn’t be allowed. Finally, the flow slows and stops. I glance down at the puddle beneath me. It is flowing between the paving stones and heading for the gutter. My shoes are soaked, and dark patches run the whole length of my grey socks.

I look up and smile politely at the gawking crowd. I give a little curtsey, and skip off back to my Miss.

When I open the car door, I’m relieved to see there are two towels laid out covering the seat.