It wasn't the first time my brother had caught me taking a photo of myself with my phone. And I fear it won't be the last.
What started as an experimental click -- sure everyone was doing it -- has spiralled into a five-click-a-day addiction that has affected my relationships with my friends and family.
Well, with my brother, at least, who was now shouting back something about me being 'soooooo vain'.
I blame the iPhone creators. They have made it all too easy for women to take clandestine snaps of themselves before erasing them as efficiently as a man deletes his browsing history.
The iPhone has supplanted the mirror for many women. Why not see how you look at your best angle rather than every angle?
But as with everything, you can get caught with your pants down, or in my case, your lips pursed into a ridiculous looking pout.
It really did just start as a means of checking my make-up; now I do it to check how my face looks in every possible contortion known to man.
Should I get a fringe again? Snap! Did that face mask make a difference? Snap! Camera, camera, on my phone, who is the fairest of them all? Snap, snap, snap.
You know something is not right when an article on the behaviour of monkeys justifies your own.
But I can't tell you how happy I was to discover that when a photographer visited a national park in Indonesia, one of the black macaque monkeys picked up his camera and took a series of self-portraits.
'It's hardwired!' I rejoiced. Vanity is a primitive drive. Monkey sees, monkey does, or something like that.
I also take solace in the fact that I don't upload these self- portraits to social networking sites. That is the point at which it goes too far.
You see, I have shame and I see no reason for Instagramming what is an incurable disease.
Is it that these people just don't know that we can tell they are self-portraits -- even with the telltale raised shoulders and the alienoid sucked-in cheekbones -- or that they just don't care? Probably the latter.
There is a line between vanity (hands up) and narcissism, and you cross it the moment you click 'upload'. "Vanity is a mark of humility rather than of pride," said Jonathan Swift. I agree. Vain people always think they could look better, while narcissistic people can't get over how good they look.
I know the difference because I was narcissistic for a short period in 2009. It happened during a trip to Buenos Aires where I received so much male attention that I thought I was Eva Peron. I even adopted a sort of royal wave that I extended to passing trucks.
I later found out that this is the Argentine way; that men there wolf whistle at women that the tide wouldn't even take out.
Of course I didn't know this at the time and I took the beeping horns and cries of "guepa" and "hermosa mujer" as fact. They say every woman has a 'moment' and this, I decided, was mine.
I even went as far as to rationalise that the rare few men who didn't give me a double take were blind, or gay, or both.
In the evening, I would send out commiserative emails to my fans, or rather the gentlemen who had passed me their business cards during the day.
"Enjoy every last minute of it," my mother told me, "because it doesn't last". 'Eh, yeah, but I'm a global icon,' I thought to myself.
My poor old mum. She spent her holiday nursing me through what can only be described as the advanced stages of Narcissistic Personality Disorder. A typical exchange went like this:
"I'd love to see Recoleta Cemetery..."
"Do you think my tan has made my teeth look whiter?"
"...it's a must-see by all accounts..."
"Or do you think I should get them whitened? How white would you say they look right now?"
I started doing sit-ups on the hotel floor before bedtime. I was in the beauty salon every second day. I genuinely contemplated never leaving this wonderful new land where I was a goddess to the masses.
When we got to Brazil I had the cheek to buy a g-string bikini. What's more, I walked the length of the Ipanema Beach in it, the words to Astrud Gilberto's famous song running through my head.
But back to Buenos Aires, where one night we were followed out of a restaurant by not one but two waiters. "Chica," they called after me.
"Here we go again," I said to my Mum. "Don't even turn around."
But they were insistent. "CHICA!"
I swivelled around and went to give them the royal wave when one of them shouted: "You didn't pay the bill!"
So hypnotised was I with my own beauty that I had simply sailed out of the restaurant, smiling seductively at my admirers.
You could say that this was an augur of things to come.
I arrived into Dublin Airport on a blustery day in March. A grey-faced air-traffic controller was the first Irish man to greet me. With a grunt. I still hadn't received a double take by the time the arrivals doors swung open in front of me. The spell was broken.
This back story may help you understand why my self-portrait habit is a concern. We don't want to go back there again.
So I need to strike the balance. A little bit of vanity is fine, indeed necessary, in this world. To have no vanity is the real problem. Or rather to claim to have no vanity.
These women are easy to spot. They go to great lengths to let you know that they only wear tinted moisturiser and one coat of mascara. It's inverted vanity, which is the worst kind.
But I digress. While a little bit of vanity is indeed fine, taking photographs of oneself is rather a lot of vanity. Even if the black macaque monkeys do it. too.
It's time to kick the habit, but I'll take one more quick snap. Just to take the edge off...