Harriet Walker: Beware guardian angels bearing gifts

I spun round to see who was talking to me and my newly acquired livid mound

We all have our guardian angels, so they say, and mine appeared to me last week in a slightly fetid swimming-pool changing-room as I was taking my trousers off. Not the most magical scenario, but certainly otherworldly.

"Oh, you have a bite!" I heard a voice ringing out across the changing-room at the precise moment I felt the need to scratch my lower back. In the rapid-fire storyboard of mundane thought processes, I had managed to give it a little scratch and wonder how tenacious the insect must have been to bite me through several layers of black jersey before I had even turned round to answer the voice.

It's very rare that I get bitten. On a holiday where every one of my friends was eaten alive, I remained totally unsampled by the mozzies. Next to my convulsing companions, I was like a depressing-looking empty restaurant at the end of a row of bustling bistros.

So when I was bitten through three layers of clothing on a day which was cold enough nearly to have killed me, let alone any tropical bugs, I was bemused and slightly annoyed. But this faded rapidly when I spun round to see who was talking to me and my newly acquired livid mound.

I had noticed her as soon as I entered the changing-room but had, in a shallow frontal cortex sort of way, allowed her outré appearance to sink straight into my head with only the fleeting pensée of, "Well, that's an unusual outfit." She was wearing lilac leather cowboy boots, purple tights, a purple tunic over a lilac skirt, with a lilac scarf around her neck and a purple cardigan over the top of the whole ensemble. On the hook behind her hung a purple raincoat.

"You've been bitten," she said again, "now stop scratching and have some lavender oil." I was still trouserless at this point and had been so visually bombarded by this woman's dress sense that all I could do was turn over the fact in my mind that lavender was, indeed, another thing that was purple in this lady's armoury. "Lavender oil will take the itch out of it," she said, dabbing something on my back. "It has many uses, thousands in fact, but it's very good for this. You'll stop feeling itchy as soon as... There! It's stopped itching, hasn't it?" As she gazed at me through lilac-washed eyelids, clutching a tiny vial between purple-painted talons, I felt I couldn't possibly tell her that I was in fact still experiencing a very urgent desire to rip the skin off the area in question and rake the bite and its environs like a park attendant does leaves. "Oh yes," I nodded, "it's completely gone away."

"You see," she trilled, waving the bottle at me. "Lavender oil does that! You must always carry lavender oil wherever you go. I'm the lavender fairy, you know, and next time you're in Holland & Barrett you will think, 'Oh, I must get some lavender oil.'" She paused for effect and I nodded, willing her to leave me alone so I could either put my trousers back on or get fully changed into my swimming costume. (Talking to a stranger in my pants was testing my prudish sensibilities to the limit.)

"Because they sell the best kind," she then added, seemingly disappointed in my response. And with that, she picked up her lilac handbag and flew out of the changing-room on lilac Cuban heels.

I waited until everyone else in there had stopped smirking and then carried on scratching my bite, marvelling at how very odd the entire exchange had been.

The latest line-up of "faces" for M&S adverts this year includes the film star Ryan Reynolds. This strikes me as odd because the thing about Reynolds is that, in terms of "face", he looks like he's borrowed someone else's and tried to melt it on to his own head.

There's a certain type of technically handsome man that I like to refer to as a face-stealer. It's when everything is in alignment, symmetrical and nice – the sort of visage that medieval peasants might think had walked out of an illuminated manuscript, so perfectly etched are all of its features – but there's still some reason to find it essentially and mystifyingly unattractive. Everything combines to make you think he isn't wearing the face properly; other examples include Craig McLachlan and Shane Warne's new Hurley-tronic phiz.

Still, Reynolds will no doubt do very well in his new role at M&S, whose adverts require only an unfazed rictus of delirious joy, which is an expression that suits almost any face. Try it some time: buy yourself a treat from M&S and stare at it for a while. There, you've got it.