"That was amazing …" I sigh triumphantly, nuzzling my head into my partner's sweaty chest.
He's giddy with post-coital dopamine and self-admiration at his efforts satisfying me.
I don't have the heart to tell him he'd never actually given me an orgasm. Not once.
Like most of the women I know, I feel quietly confident I could win an Academy Award for all the convincing orgasms I've faked.
"Well, my wife has never faked it. I'd know."
That's the typical response I get from men every time I write about this topic.
"You obviously haven't met me. I can give any woman multiple orgasms," is another popular one.
In fact, if you were to read the comments section of just about anything I've written on the female orgasm, you'd be convinced womankind are one very sexually satisfied bunch.
Unfortunately, research paints a far more depressing picture. Studies estimate at least one third of women experience pain during sex, while a report in the Archives of Sexual Behaviour shows only 65 per cent of us usually orgasm from it (compared with 95 per cent of men).
And that's really just the tip of the sexual inequality iceberg. Because men and women have vastly different interpretations of what actually classifies as "good" and "bad" sex in the first place.
Men tend to define bad sex as passive or boring: "She just lay there like a starfish." For women, the bar is considerably lower. Accounts of "bad sex" I hear from girlfriends include words like "pain", "pressure" and "violation".
Conversely, "good" sex is typically described by men in terms of the quality of their orgasm, while for women, it's defined as the absence of pain.
This gaping disparity is known as "relative deprivation" — a psychological phenomenon in which a subjugated group is essentially conditioned to expect substantially less than their privileged counterparts.
And it's notable because in order to understand why women routinely fake sexual pleasure, we need to first acknowledge that we've created a culture that minimises and dismisses female pain.
From their first sexual experience, young women are told to expect discomfort as a part of sex — that "losing your virginity will probably hurt". The subtext being we should grit our teeth and get on with it.
We're taught to submit our bodies to suffocating shapewear, age-erasing needles and tendon-deforming heels. That, if we go braless and barefaced, we'll be viewed as less professional at work and less desirable on the dating scene. Despite men achieving both these feats while dressing for comfort.
On average, we wait longer to be treated in the emergency room, are given effective pain relief less often and classified as "less urgent" than male patients.
And while you'll find 24,675 PubMed research papers on erectile dysfunction, you'll get just one fifth of that on dyspareunia — the acute pain around 20 per cent of women experience during sex.
Women don't pretend to enjoy bad sex because we're liars. We do it because it's never occurred to us our comfort matters to anyone.
When you've spent your entire life acclimatising yourself to physical discomfort in order to please others, it makes sense your orgasm is going to fall to the bottom of the priority list.
Experts — typically male — like to argue lack of female sexual pleasure stems from biology; that we're just not wired to enjoy it like men do. This is embedded in the tired idea women exchange sex for fidelity rather than, you know, actual enjoyment.
But there's little scientific backing to this theory. While most women take up to 20 minutes to climax during sex, when we masturbate, it's just four — the same amount of time it takes men.
Indeed, the issue isn't that we're incapable of enjoying sex (quite the contrary, most of the women I know masturbate frequently), it's that we've been taught to prioritise the male orgasm at all costs.
Feigning pleasure is a cost-effective strategy for women. It brings discomfort and pain to a speedier finish, spares our partner's ego and earns us a metaphorical gold star in the job we've been trained to perform since we were girls: pleasing men.
It's tempting to place the burden of responsibility on your female partner for faking it. To assert that, actually, it's not your job to read her mind, and if she wasn't enjoying it, she should have piped up sooner. Male readers often email me with this very grievance: "My wife can talk my ear off all day. Why does she go silent when it comes to sex? It makes no sense."
But the truth is, it makes perfect sense.
It's completely logical why a woman — who will spend on average seven years in debilitating pain being dismissed by doctors before receiving a diagnosis of endometriosis — wouldn't ask for what she wants during sex.
I stopped lying about my own sexual pleasure after my marriage broke down. Call it a quarter-life crisis, but it finally dawned on me after shedding my title as a wife, I didn't have to stick with something that was causing me pain.
These days, if the sex with my boyfriend is sub par, I'll nuzzle into his chest afterwards and softly say, "I love you, but that didn't do it for me. Next time can we try something different?"
It still feels unnatural, but I push through the discomfort anyway because, as it turns out, it's far less painful than faking it.