After 20 years behind a camera, you can spot the signs. I see marriages doomed to fail even before the confetti falls, fathers shaking their heads in disappointment, grooms with a roving eye and bridesmaids who know too much.

Behind my fixed smile, I can't help thinking about what lies ahead for the couples I'm photographing. If one has been divorced before, will history repeat itself? How will the children adapt? I see a lot of children from first marriages looking anxiously at the new family configuration that awaits them.

Sometimes you don't have to wait long for the first family argument. If there's a bad atmosphere, I wonder if it will all kick off at the reception; it usually starts there after too much champagne on an empty stomach.

I'm often surprised at the amount of competitiveness involved, the obsession with class and money. I see snobbery, antisocial behaviour, one-upmanship. Often people overspend and I wonder at some lavish weddings if the marriages are going to last long enough to repay the debts. But there are plenty of happy weddings, too, usually the smaller, more intimate, less pretentious ones. The cheaper bashes don't raise expectations and people are more relaxed. Sometimes I even get to witness pure, unalloyed joy.

Often, though, it can feel as if I'm witnessing a war zone. Then I'm relieved I'm behind the camera and not one of the wedding party myself.

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