'HE SAID what to you!" I was visiting a friend whose baby was eight weeks old and her husband had just rung to inform her he would be out with the lads for the third night that week.

Smugly I told myself my husband wouldn't do that to me. He cooked dinner every night and did the washing up. I was about eight months pregnant then. Three months and four hours sleep later my relationship didn't seem so equal. Not only was he nipping down to the local after work to catch up with friends, when I had been breastfeeding every three hours for the past eight weeks, but that morning he had told me "we" needed "a system" for the pile of drying baby grows I had left balanced on the edge of the radiator overnight.

I rang my mother to complain. Normally very happy to see his downsides, she came back with, "Well dear, are you giving him enough sex? Men just need it, you know?"

If I had had the time I'm pretty sure this is when I would have killed myself.

As it turns out it wasn't just me who felt like I'd been cast back to the 1950s. I attended a breastfeeding group that often turned into an all-in rant about how daddy was disappointing.

What had happened to our equal relationships? How had this new man suddenly gone cave? Why did I care about tucked in sheets and worry about cold viruses like they were the plague?

That's when the tactics began.

Scorekeeping: "I've got up to the baby every morning for the past 10 months and you've done it once."

"Well I gave him his bath every night last week, even when I was tired from work."

Escapology: "Why has he suddenly decided he needs to train and run a marathon when the baby is 10 weeks old?"

Nighttime Chicken: "If I just pretend to be asleep this time he'll have to get up to the baby."

How come nobody told me about this? Where is the literature on it?

This was also the question that Dublin-born Cathy O'Neill and her two friends, Stacie Cockrell and Julia Stone, were asking when they decided to write a book about exactly what happens to a marriage after a baby.

Time to surrender I met Cathy at the Merrion Hotel, where she had secured a table when none seemed available. Incredibly neat and pretty, she exuded grown-upness, an attribute hard sought after by new parents struggling to cope with being responsible.

I, for one, have not managed to put on make-up since BB (before baby).

It was hard to imagine Cathy, who moved to Texas after a five-year transatlantic courtship and now runs her own consultancy business, having struggled with anything. But with two babies under her svelte belt she decided to blow the lid on the silence surrounding what her book calls the "baby grenade" in her marriage (and everyone else's).

"I should say from the outset we all love our husbands and they are fundamentally good guys - but they are men and we are women and hence the disconnect that happened after a baby. What was really important to us was trying to figure out [our husbands]. I know he's not a closet chauvinist. I know he's not, so why is he coming out with this stuff? Where's it coming from?"

She admits that she also changed, becoming more uptight when the "Mummy Chip" in her brain kicked in.

"When Kate [her firstborn] was about eight or nine weeks old and asleep, Mike [her husband] says hey will we go get a video? So we go get in the car. We were about to go into the video shop when I thought, 'Good God! We left the baby at home!' I just completely forgot we had a baby. Just completely forgot we were parents. He of course said, 'We're here now. Let's just get the video.' To say I was appalled is an understatement. And I was so upset; I cried and he couldn't understand why I was so upset. It doesn't get much worse than to forget you have a baby, so I ran home and she had been asleep the whole time.

"It just underlined how different we had become. He was relaxed about it and I was just? I think it was normal that I thought it was horrific that I had left the baby at home."

Normal indeed, for a mother. Mike's reaction was just as normal for a father - who, let's reiterate, loves that child just as much but doesn't approach parenting in the same way.

Seething resentment towards each other may sound incongruous to the uninitiated when discussing the happy arrival of your bundle of love. But those who have recently been plunged into parenthood will recognise it only too well.

"I really resent that he wants to take off for five hours to play golf, " Jane, a mother-of-two married for nine years, tells Cathy in the book. "Then he expects me to be OH so grateful when he watches the kids while I go to yoga for an hour. Big deal."

One answer to these feelings of resentment is - again, according to the book - "surrender." What are you saying, Cathy? That women should say, 'OK I'll clean the toilets for the rest of my life and just be happy about it'?

"No. Surrender means stop trying to get your old life back. The level of freedom that you had is gone and you could drive yourself nuts trying to get that back. You are in a new chapter of your life now. You'll have that freedom again. So the surrender is just? embrace this.

This is life now and it doesn't mean, for women, age 10 years overnight. It's just accepting: I'm a mum now, he's a dad and we have responsibilities and we have to be selfless."

The Five Minute Fix Cathy assures me she is talking about men as well as women. The book is addressed to both genders, though I have a suspicion that, come publication date, men across the land will suddenly find this book opened to the relevant page and lying across something he generally uses for domestic escape: his laptop, the toilet, propped up against the television when Top Gear is about to begin.

So what about men? And - we've been dancing around the subject for long enough - what about sex? Surely men are being unreasonable with the '10 o'clock shoulder tap'?

"We deliberately put men first in the chapter about sex because the issue is more important to them than it is to us, at least on a surface level. The most eye-opening thing for me was to hear them say, 'the wheels are falling off, ' 'the sky is coming down' or 'you have no idea how bad it feels.'

"I thought, oh god I never knew."

"But you're hearing from women, 'I'm exhausted, there's no romance, no foreplay - what does he expect?'" What indeed? You suggest 'The Five Minute Fix'. In other words, a blowjob. Ominous sounding idea.

"The Five Minute Fix: I think it's one of the most virtuous acts a woman can do. It's not for everybody. But hey, you've got five minutes. You can pick up the laundry, read a magazine, watch a bit of TV. . . or take care of him - and the benefit of doing that is so huge. We had the guys saying, 'That would transform my marriage - would you call my wife now and tell her?'" "Bottom line: it works. It's only five minutes and it's not a big deal!"

Hardly a feminist statement, is it?

"Oh my goodness! Umm?probably not, probably a die-hard feminist would hate it because you're supposed to have sex on your terms: when you want and conditions have to be perfect. We don't have a political agenda. That idea came from the three of us talking and realising, 'You know what, it's kind of undervalued by women.' It really doesn't take very long. He's thrilled and it gets him off my back. It was looking at it from a different angle."

She catches my expression, looks up at me and laughs, "I've personally had friends lobby to have that page taken out."

I mention to Cathy that one of my friend's husbands runs marathons while another's plays a lot of rugby. She nods sagely.

"Escapists."

The book has various categories for how men and women cope or avoid parenting duties. I didn't have the heart to confess that I read the 'Top Ten Convenience Cards our Husbands Use' with growing unease as I recognised not my husband but myself in some of them. (TV. The kids can wear their PJs all day; we're not really going anywhere. Do we have to comb their hair? ) Much of what the book, and Cathy, prescribes boils down to chilling out, especially women who feel the home has to be perfect and men who feel trapped and want to run away.

Breaking the silence "There's lots of hope. The book is intended to be positive and solution-focused. The first thing to realise is it's just a stage. You are adjusting to who you are as a mum and dad. Also, there are small things you can do. If the big issue is he seems to be straining at the leash, give him some down time. Don't beat him up for it. When it comes to household chores, do a divide and conquer approach, factoring in how much a person's job wipes them out.

There's no way in this day and age one person should be dealing with all the crap in the house.

"We've said in the intro to the book that the kids themselves are never, ever the problem. It's the way we respond to being parents. There are so many lovely moments when they are small."

Those moments are focused on with microscopic vision BB. AB (after baby) reality is somewhat different, but nobody tells you about it. When our baby was a couple of months old I started brooding over the fact that we had never done one of those pre-marriage counselling sessions. I was convinced at that point that we would have failed it miserably (though now we've both had some sleep our prospects are distinctly rosier).

Should people know about this before they get into the whole messy business of raising kids?

"My sister is 30 and single and she said, 'Cathy is your intention to scare people not to have kids?'

"Then I gave the book to a male friend of mine who is 31 and has a serious girlfriend and it scared the hell out of him. I thought, hang on, do we need a warning label on this thing? Because to somebody like you reading it you're nodding your head and thinking, 'Absolutely this is what it is like.'" Grannies and grandads are complicit in the duplicitous cover up of AB chaos in marriage. "Veterans [of parenthood] don't want to scare you before it happens because you don't have perspective for it. Our parents' generation were much better at sucking it up and putting the head down. Also they want the grandkids now so they're not going to throw a spanner in that.

"Also, people forget. By the time their youngest kid is five they've forgotten and they're saying, 'Oh I'd love another baby.'

"It is a global conspiracy of silence and we're cracking it open."