In which I know of a lawful impediment

To be printed 21/04/11.

Next weekend, I am going to a wedding. It is not - just to clear up the matter now before you start imagining me far horsier and more secretly double-barrelled than I am - the royal one. It is another wedding. You don't know them.

More interestingly, I don't know them either.

I am going as that ever-mysterious and alluring figure, the plus-one. I've always wanted to be a plus one. Partly because it means my company is valued highly by a loved one in the areas of dancing, eating posh food and giving witty commentary on people's hats, but mainly because it means I can spend the whole day trying out variations on my hilarious "oh, I'm just here for the booze" line.

Never having met either of the happy couple puts me lower than the catering staff in terms of relevance to the occasion, but about on par with them in potential to ruin it. There's a whole catalogue of potential faux pas that I'm trying to identify and quash before the big day.

For example I probably shouldn't, I'm guessing, catch the bouquet. This would be better left to someone with a little more claim to the honour, such as a friend who has endured months of bridezilla behaviour and wants revenge. Or the weeping, lipstick-smeared unfortunate in the corner of the dancefloor singing It Should Have Been Me. Besides, I'd go swiftly from mysterious plus one to bonafide stranger, next to a boyfriend-shaped hole in the marquee wall. Not a plan.

I also shouldn't, as a general rule, pull focus from the bride. Nobody should of course, but at least if it's her cousin that turns up in a gold lamé catsuit and three-foot stuffed vulture headpiece it can be bitched about at years of family functions, rather than lamented in photos with a bitter "Who was that?" "Some hag nobody knew."

But as a normal human being, of course my main fear is that I'm going to scream something inappropriate at the top of my lungs during the ceremony. We all harbour this fear, the fear of Sudden Uncontrollable Public Screaming (or SUPS) - anytime we're in a church, or meeting, or school assembly or other generally quiet and non-screamy occasion, a tiny voice in the back of our minds asks "what would happen if I stood up now and yelled something obscene?" It's the same voice that wonders about jumping off railway bridges or spontaneously dumping ketchup down a stranger's white blouse.

"It would be bad," you tell the voice. Because you are sane, and normal. "Yes, it would be bad." replies the voice. "It would be very bad. Let's picture just how bad that would be." And in the midst of the spiralling disaster scenes playing out across our minds, we convince ourselves that we are definitely going to do it. We are going to scream the obscene thing.

So when it comes to the "If any person here present knows of any lawful impediment" bit, despite all my best efforts to be poised and charming and avoid the boyfriend-shaped wall hole, I fear the urge to scream, "BECAUSE HE LOVES MEEE, AND ALSO KILLED THAT MAN THAT TIME" is just going to be too strong. But it's ok, I'm only there for the booze.

And just think of all the colossally dreadful SUPS people will be battling to surpress during the royal one. Good luck, Beckhams. Hold it in.