1. Not all her underwear matches
Non-cohabiting men live in a state of blissful ignorance about their girlfriend's underwear. Given that every time her sees her, she's wearing a nice, new(ish), matching set of sexy undies, he naturally assumes she has a 14-day supply of them. Then, he moves in and discovers the truth: she owns two sets of expensive 'going-out' thongs and a bulging drawer full of comfy M&S big pants which, it transpires, are her standard attire. As time goes on, her undie standards slip, until, one day, he finds himself sitting on the sofa with a woman sporting holey, grey, granny-sized drawers, washed so many times they look like a mammoth cobweb.

2. She's incapable of throwing away clothes
Before she moved in, my girlfriend asked me to 'help' her throw away some old clothes. This involved her holding something up, me saying, “Chuck it” and her responding with a curt, “Oh. So, that means, when I wore it last week, you hated it, but didn't say. What else of mine do you hate, then?” I think that's what you call a no-win situation. Her wardrobe has garments purchased two years ago that still have the label on and items from the same shop in exactly the same style but in six different colours. Then, there's the stuff that “might come back in”, the stuff that “could be worth something some day” and, by far the most hilarious excuse of all for hoarding old tat, “If I have a daughter, she'll need some old clothes to dress up in”. I wasn't there to 'help'. Oh no. The whole exercise was just a bargaining tool to get her a ridiculously unfair chunk of our shared wardrobe space. In the end, I was the one who had to throw out clothes to make room for hers, and I hardly had any to start with!

3. She plays your albums to death
Personally, I like to listen to music pretty much all the time. Yes, I may have a newly-bought favourite album which I play a bit more than the others, but generally, I give most of my CDs a run-out at some point. My girlfriend doesn't. Not only does she rarely listen to an album the whole way through, preferring instead to skip to her favourite track and play it again. And again. But, I have also discovered, to my horror, that she generally listens to one album exclusively for up to six months. Indeed, so far, I've had a three-month audio jail sentence of Ms Dynamite. Meanwhile, my girlfriend dismisses my entire record collection, which encompasses 40 years of soul, funk, folk, indie and alternative country, as “that weirdo guitar music you listen to.”

4. She cries at anything
“Baby, what's wrong?” I said, full of concern when I returned home to find my girlfriend in floods of tears. What could it be – a death in the family? “It's... (sob)... it's... Wellard!” - the tears cascading down her cheeks as she explained Robbie's dog had run away in an episode of EastEnders. Okay, so missing pets make me sad, too, but the fact is, she cries practically every time EastEnders is on. If it's not Wellard, it's Dot. I'd better make sure they never show Bambi on TV, or we might drown. I'm not saying there's anything wrong with venting emotion – I've been known to sob in front of the TV myself (mainly during England matches), but I find myself wondering, if EastEnders makes her so upset, why does she watch it?

5. She's messier than us
For years, the myth has existed that men are slobs and that all women float around in domestic environments of show-home perfection. Indeed, when a moderately tidy bloke finds himself moving in with a woman, he worries that he'll end up living under an oppressive tidiness regime. Ha! Quite the reverse, in fact, as she descends on their home like a bomb in a knicker factory. Also, women crow about being faster at washing up than men, but there's a good reason for this – they don't do it properly! They leave encrusted bits of pasta all over the place and never rinse.

6. She's a big fat piggie
From a food point of view, moving in together spells the end of eccentric snacks (peanut butter straight from the jar), emotionally charged nosh-ups (an entire tub of ice cream and half a loaf of bread because she had a bad day at work) and lame, povvo meals (spaghetti with HP sauce, anyone?). Suddenly, she has to pretend she's a domestic goddess who whips up chicken livers and ratatouille every night. The other thing you'll note is that newly cohabiting couples always get porky. This is because love and feeding your face are inextricably linked (I'm sure Freud had a few words to say on the subject of enjoying a good stuffing), but it's also because in our me-me generation, we don't like others eating things we-we can't eat too. If I eat a plum, my girlfriend will look at me with an odd expression, then a few mintues later, take one from the fruit bowl and noisily eat it. Obviously, the logical conclusion to all this, given that we do about the same amount of exercise, is that, sooner or later, we'll end up weighing exactly the same.

7. PMS isn't nearly as bad as everyone says
On a positive note, the one thing I was really fearing that has proved to be an exaggeration was PMS. Yes, my girlfriend has been a bit ratty on the odd occasion, but she's never actually tried to stab me with a bread knife. And, the fact is, as long as I'm warned in advance, I know to a) cut her a bit of slack, b) be extra attentive, or c) go out. The other thing they don't tell you in bloke-school is that plenty of women become a lot more amorous just before their periods. The Lord giveth and the taketh away. While we're on the topic of sex, the other thing they don't tell us is that sex with someone gets better the more you do it. Which makes living together a great idea. Move in together and all those hours you would have spent travelling across town on the bus can now be spent far more productively in the pursuit of hot duvet action.

8. She never asks a direct question
The other day, my girlfriend turned to me and said, “My mum says if we wanted to go down and see her at some point this summer, it would be cheaper to book the tickets now. She had a quick look on the internet and says there are some good deals for a few weekends' time.” Translated into bird-speak, this meant: “Are you prepared to come and visit mum on 5 August?” Similarly, when she says, “Mum reckons now is a really good time to by property. She thinks I should go and see my bank manager,” what she's actually saying is, “Do you love me enough to contemplate getting a joint mortgage at some point in the near future?” Thus, all 'heavy' questions are presented as observations from a third party to avoid any accusations of 'pressure'.

9. When it come to buying new clothes, she treats you like your dad
Women are trained from birth to be deliberately vague about retail-therapy trips (“I needed winter clothes” translates as “I just blew half my wages on a white coat that needs dry cleaning after every wear”). I have actually caught my girlfriend coming home and trying to sneak shopping bags into the bedroom, which is utterly ridiculous. As if I care what she buys! I mean, it's not like we have a joint bank account. In short, they treat us like their buyer's conscience. And, yet if we do ever question the wisdom of a purchase (Are you sure you're going to wear that red corset?) she'll fly into a rage and accuse us of trying to stifle her individuality.

10. Being a woman is ridiculously time-consuming
I'm not talking about that tired, old cliché about women taking ages to get ready – we knew about that already. It's all those mind-boggling things they fill their lives with that we were totally unaware of. Hand washing, for example. Who in their right mind has a wardrobe full of items which need to be hand washed, rinsed and hung up with as much care as you'd use to hang a Van Gogh? Then, there's the half an hour spent transferring possessions from one handbag to another – failing, of course, to remember keys, credit card, mobile phone and all the vital things (which they only discover once they've arrived home cold, hungry and locked out, while we're at the pub). Oh well, it's a good job we love them.