We get up from the cafe. I’ve slipped my foot, with my toes covered in Chloe's cum, and all back into my sandal, and we walk towards the car park. Chloe suddenly puts her hand to her head and spins around.

“We forgot to get new panties, Mummy.”

“Please, Chloe,” I beg. “Can’t we go home. I’m desperate. You’ve been edging me all day.”

She gives that malevolent grin I’ve come to recognise over the past 24 hours and slowly shakes her head.

“No, I’m sorry, Mummy. You did promise I could get new underwear.”

I sigh in defeat and follow her, watching her ass sway in her little white skirt, knowing she wasn’t wearing any panties, hadn’t been in fact since the clothes shop and they were crumpled up in my handbag at this very minute.

She moves at speed up and down the aisles. It’s clear she has a style or colour in mind, and I decide to wait and watch. I glance at some of the other girls and women choosing underwear and begin to visualise them wearing it. The thin girl with the long blonde hair holding up the bright red hooker knickers and matching bra. Good decision, I think when she puts them back and selects a black set instead. Or the teenage girls flicking through the rack of lace thongs, giggling as they lift one out and hold it in front of them. Or the tired-looking woman pushing the toddler around in the buggy, trying to stop him reaching out to pull the knickers off the hangers. It was probably one of those red sets that got her in the family way, I think to myself.

A shadow passes in front of me, and when I look up, Chloe is standing with her hand out. “Come on, ATM, I thought you wanted to go home.”

I blush at her casual observation that I am just a cash source for her.

“Don’t you want to try them on?” I ask, but she just shakes her head.

“I know my size, and you said you wanted to get home.” She pauses and smiles. “So, I bought what I thought looked nice. I will try them on for you later.”

Finally, we leave the shopping centre and begin the drive home through the Saturday afternoon traffic. The radio is playing ‘Fairytale of New York’. We are both singing along but after singing about scumbags and maggots, she turns and announces that it isn’t really very Christmasy, singing about sluts passed out on heroin.

"It's a love song, darling, it’s about surviving adversity,” I tell her, perhaps a little patronisingly.

“Yeah, well, it’s about a christmassy as a Die Hard movie.”

“Do you know how the Pogues got their name?”

“No, I’ve no idea what it means.”

“It’s Gaelic. It’s one of the few Gaelic phrases I know.” I turn to look at her, then continue. “They were originally called Pogue Mahone. But then a Scots Gaelic listener phoned in to complain to Radio One in disgust at the presenter saying such a rude phrase on the radio at half-past two in the afternoon.”

Chloe’s interest is piqued.

“So what does it mean?”

“Póg mo thóin means Kiss my arse.” I laugh at her shocked expression.

“So they banned them?”

I shake my head.

“No, it was just after they’d banned Frankie Goes to Hollywood for their song Relax which was all about gay sex. It topped the charts for weeks despite the ban, so they just didn’t mention the Pogues at all.

“So that’s why they shortened their name to The Pogues.” Chloe smiles at the thought of a secret phrase for kiss my arse.

“Of course, it wasn't the first time the singer had to change his band’s name. He was also in a band called The Nips. Any idea of the original name?”

Chloe giggles and thinks.

“Something to do with Nipples,” she pauses, “or Japanese people?”

“Right the first time,” I laugh. “They were called the Nipple Erectors. Very punk rock.”

“Was he a punk? The Pogues don’t sound very punk rock, it’s all diddly dee music, isn’t it?”

“I think they would describe it as punk folk.”

I pull into the drive and turn off the engine. It’s been nice just chatting with Chloe. It doesn’t happen very often, and I feel a warmth towards her. Then she picks up her phone and gives my pussy another buzz.

“Fuck,” I gasp.

“Let’s get inside, Mother. We haven’t got all day.”

She unclips her seatbelt, picks up her shopping bags and heads into the house. The vibrations cease, and I wonder if she is out of range of the vibe or if she turned it off. I lock the car and follow her in. As I hang up my coat, she calls out from the utility room, “I’m in here.”

She’s leaning against the worktop when I go in. She’s her arms folded and one foot is crossed in front of the other. She looks almost disappointed, like I’ve done something wrong. I notice the phone is sitting on the worktop within easy reach, and the knowledge she has complete control over the vibe in my panties sends a shiver through me.

She reaches down and lifts her skirt, showing me her shaved pussy once more. Then she turns around.

“Do you like my bum, Mummy?”

Oh god, I think. What sort of question is that? Of course I like her bum. I’ve been staring at it for months and now she is leaning over the worktops and pressing her ass out, displaying her tight little butt cheeks to me.

“I do, Chloe,” I manage to whisper. “It’s a beautiful bum.”

“Póg mo thóin.”

“What?”

“Póg mo thóin, Mummy. Now.”

How could I refuse her? It was basically an order. I sank to my knees. Had it really only been twenty-four hours since she had caught me kneeling, sniffing her used panties? Twenty-four hours since my life and my relationship with my step-daughter have spiralled out of control?

I gaze at the smooth alabaster-white ass cheeks. A perfect, tight little teenage ass. I slide both hands over her cheeks, then squeeze them. I’m rewarded by a low moan of pleasure from Chloe. I grip the cheeks and move my hands in circles, spreading them open, then pushing them together. I trail the tip of my forefinger through the cleft in her cheeks, tracing her crack, feeling the dampness from sweat.

The way she squirms and flexes her cheeks emboldens me to go further. I let my finger glide further in, grazing against the puckered entrance. Her soft moan signals her desire, and I grip both cheeks and spread her open. Her star winks at me, and I stretch out my tongue and give it the softest lick with the tip of my drool-coated tongue. I pucker up my lips and kiss her softly.

“Don’t stop.”

It’s hard to tell if she is ordering me or begging me. Either way, I don’t want to stop and kiss her puckered teenage asshole again and again. My tongue flickers out, French kissing her arse as my tongue tip swirls and licks the puckered ridges.

It doesn’t taste of much, of damp skin with a faint musky hint but it is the act that is making me drip. I can see myself kneeling, kissing and licking my teenage stepdaughter's ass. It is at this moment that I realise I would do anything she tells me to. I’m completely in her power, and the scary thing is that I know she knows this too.

“You’re such a good little ass-kisser, Mummy,” she moans as I rim her star. I merely mumble my agreement as I bathe her asshole in my drool. Her hand wanders down and rubs her clit as I pleasure her from behind. It’s so wrong, but I can’t help it. It’s gone too far to stop now. I should have stopped it when she caught me sniffing her panties. Stopped before I kissed and licked her to orgasm through them.

I shouldn't have taken her shopping and watched her strip and try on dresses. I shouldn’t have let her tease me with her foot as I gazed at her shaved pussy. I definitely shouldn't have let her buy vibrators and god knows what else in a sex shop. I shouldn't have rubbed her clit with my toe until she came in a cafe and right now, I definitely shouldn't be kissing and rimming her asshole. She's my step-daughter. She's only sixteen, and I'm married to her father. It’s all so so wrong, and as I watch her shake and convulse as the orgasm ravages her body, I don't care. Even the realisation that she hasn't let me cum all day, constantly keeping me edged and needy doesn’t diminish the lust I have for her.

As her orgasm subsides, I sit back on my heels and kneel, watching as she recovers. Finally, she straightens and lets the dress fall down, obscuring her perfect ass. I can feel a sheen of juice on my chin.

“Oh look, Daddy’s home,” she giggles. I hear the car pull up on the gravel drive outside and quickly wipe my chin and try to make myself look presentable. She grabs the shopping bags and skips off but not before promising to show me what she has bought for me later.

I wave at my husband through the utility room window as he struggles to lift his bike off the rack on the back of the car. When he comes in a few minutes later, he apologises for being so sweaty and heads off to the shower and I’m left alone, wondering just what am I going to do about his daughter and what she has unleashed in me.

My phone pings but when I open the picture my heart stops. There in technicolour detail is a close up picture of the pussy I’ve been looking at all day. Chloe’s fingers glisten with her juices as she spreads her swollen and puffy labia open revealing the pale pink whorls inside. Her index finger also glistens, and it is clear it has already been buried deep inside her.

Then the vibe in my knickers erupts once more. It is more intense than earlier and I have to grab onto the door frame for support. I’m starting to bend over, the urge to cum building so rapidly. And then, just when I’m sure it is going to burst over the dam, she cuts the connection.

“Fuck,” I snap in frustration at my own impotence. My phone dings again. This time, a text.

IF you don’t want me to make you cum in front of Daddy, you best come up here now

I swallow and hurry upstairs. I can hear the shower going in our en-suite as I cross the landing to Chloe’s bedroom. I give a quick knock and enter. Chloe is standing, waiting for me.

“Give me the vibrator.” She holds out her hand and waits while I have to lift up my dress and firk my hand about in my knickers to extract it. I hand it over, feeling ashamed that it is soaked in my juices.

“Please let me cum.”

Fuck, I sound so fucking needy, but at this stage I don't care. I try again. “Look, Chloe, you've had your fun, but this needs to stop now. Your dad is home, and enough is enough.”

Her face darkens, and she steps close to me. Her eyes are ablaze with anger or indignation as she snarls, “Listen to me, you fucking bitch. If you don't do as I say when I say it, Daddy just might find out.” She trails her finger down my front, pressing the dress fabric into my cunt. “And we both know you don't want that, don't you?”

I swallow and nod.

“He mightn't believe you,” I try.

She cuts her laugh short, and she changes her expression to thoughtful consideration.

“OK, let's ask him. I can show him the picture of you kneeling, holding and licking my panties.”

She scrolls through her phone and shows me the picture she took yesterday.

I slump in defeat. “Let's not,” I concede.

“Let's not,” she agrees.