I don't cheat, okay? Let me say it again.

I. Do. Not. Cheat.

The same way I don't drink-drive or wear yesterday's underpants. It's a built-in rule and one that with a little forward thinking is never broken. I'm engaged now to Alice and our relationship couldn't be stronger. It's built on honesty and it's built on trust, got me? We have a varied, healthy and satisfying sex-life and we don't screw other people.

End of story.

This is most reassuring when, for example, I end up talking to the new temp across the photocopier at work. Or when I go out drinking with mates at the sort of club where randy, dissatisfied wives and girlfriends go to prove they're still attractive to other guys. The subtle explanatory reference is never far from my lips, should I fall into conversation with such ladies: 'I was on holiday there with my girlfriend.' Or the more direct 'Thanks, but I'm already with someone,' if required. And then there's that old faithful back-up: 'Yes, but I'd know, even if she didn't.'

Nothing is ever going to happen.

This is especially good to bear in mind on a day like today. One of the days when I visit Bella. In fact, no - that's not even a cause for mild concern. Bella's in a relationship as well, and she really likes the bloke. He's quite the romantic, it seems. Last time she told me all about her high expectations for Valentine's Day and I in turn described my plans for Alice and myself. The two of us, client and professional, sharing the same warm glow from our respective love affairs. So the Bella situation is nothing to worry about.

Okay, all right - so the reason we ended up talking so earnestly about our significant others was to deflect from a certain...frisson that passed between us. Now hold on, I didn't hit on her - don't think that for a second - and she didn't take it as such. I passed some vague compliment about her loose perm suiting her, or something like that, and she took maybe a little too much pleasure in it and then I held eye-contact a longer than was perhaps wise... And then it was all embarrassment and rapidly changed subject and very deliberate mention, on both our parts, of the people we were involved with.

Well massage is intimate after all, even purely therapeutic massage. Bella is a consummate professional; she's friendly without being flirtatious, very careful to keep that businesslike edge. But after several sessions you get to know each other a bit. And if you have a natural connection and a degree of mutual attraction, however unspoken, well, anyone's guard can drop. Okay, it's true - I did carry her final smile with me for the rest of the day. And that night. When I was...having sex with Alice. There I was, my body moving on my fiancée's, and when I closed my eyes, Bella's smiling face was floating before me. Alice's moans and Bella's smile... Shit, look, I mean everyone has those thoughts! It's not as though I deliberately dwelt on them...

And - and - why the hell am I even feeling guilty? The massage sessions were Alice's idea in the first place. She was driving the bastard car when the accident occurred! If she hadn't braked to save that frigging pigeon, we wouldn't have been back-ended, I wouldn't have whiplash, there'd be no need for bleeding massage therapy! And I haven't even done anything yet. Not that I'm going to!

Like I said, nothing is ever going to happen.

What do you think? Should I continue?