Why is it that old Flames still have the X Factor?

Ask any single man what he fantasizes about and he'll make up something about a celebrity. It's easier than the truth. I'd probably tell you mine includes a pool full of custard and all three Charlie's Angels. But in truth, the best male 'mind movies' star an ex. I know mine do.

But why would an ex be that appealing? The last time you saw her, she was crying rivers of mascara, the way an octopus leaks black ink when it's pissed off. Yet, in happier days, your sex life was like a Strictly Come Dancing final: two misfits performing a perfect routine - with massive grins at the end. Unforgettable.

Sadly, I was skating on thin ice with Naomi. Apocalyptic arguments started eclipsing the good times, and I just couldn't 'get' her vegetarianism. She said we shouldn't contact each other for a while ('like, forever'), and all I had left were memories of her tarty witch outfit at a Halloween party and that naughty weekend in a hotel.

Because a man's girlfriend memory is selective, I forgot about the tofu burgers and started wanting her back. And with today's technology it was almost impossible to maintain radio silence. Not with the wonders of Facebook.

The Truth is out There - And It Hurts

Language emerged two-and-a-half-million years ago, just after Homo erectus learnt to whittle tools. He turned to Ms Cavewoman, grunted and pointed to his bedroom with a hairy finger. Minutes after discovering speech, man had invented courting. And since the spoken word there has been no bigger revolution in dating than Facebook.

'Naomi is going underwear-shopping', my newsfeed informed me. Then, 'Naomi is opening some vino', which simply reminded me how saucy she gets on wine. I began to wonder whether she'd be going to bed on her own - then the poking started. In my dad's day, you'd have to phone a girl's house and get past her old man before you could have a chat. If you wanted to dump a girl you'd simply change pubs and hope she didn't find you. Aah, the days before Facebook.

So, after days of digital tickling, Naomi and I began a game of online Scrabble. I laid down 'kiss' (eight points) while she had 'whips' (17 points - double-letter score). Were we really flirting through a board game? Singledom and working only with men meant I hadn't seen a real girl in weeks - so even this was exciting. Plus, Naomi was really pretty. In fact, I used to like just looking at her. My selective memory was at it again.

'Why did you want to meet me now?' Naomi asked as we moved from virtual to reality. Sitting in the pub we used to go to, it already felt familiar - the same barman with the same moustache.... 'I was waiting for the right time,' I lied. You see, the rules for meeting an ex are simple - and involve fibbing. The reason should be something like that CD you need. Or whatever. The girl must dress like a million dollars but say she 'threw something on'. The boy mustn't ask whether she's dating and, if asked, both parties must say they haven't looked at anyone since. It makes it so much easier.

Back in my bedroom, everything with Naomi was wonderful. The reason your ex is so appealing is her expertise. She is express sex. Men reopen the ex files - instead of going for someone new - for that quick boost. It's faster than weeks of dating, slowly proving you're not an axe murderer.

But second time around I still irritated her with my pro-steak attitude and the same old jokes. Naomi obviously felt this was our final curtain call and cut me off her Facebook altogether. Yup, I've been defriended. Ouch.