Ring of fire

My partner and I have been together 12 years. We share three children, a large mortgage and a supermarket loyalty card. One thing we don't share, however, is a marriage certificate. The reason is simple: we are both convinced that marriage is the kiss of death for a long-term relationship. And we're not alone. In a recent British Household Panel survey, two-fifths of cohabiting adults perceived advantages in living together rather than getting married. Add to this the fact that marriages that begin after cohabiting tend to break down sooner than those that don't and you've got a compelling case for continuing to reside in sin.

Think about it. If you've been living together for a while, what reason could you have for suddenly deciding to jump the broom? Either something's going wrong in your relationship and you're hoping marriage will stop the rot, or you just fancy donning a great big white meringue and acquiring a decent set of dinner plates. Neither is a great reason for making the ultimate commitment.

In Bronwyn Howell's case, marriage was a last-ditch attempt to save her relationship. "Joe and I had been together since university. We had an awful lot invested in our relationship, not just in terms of the home we owned together but also mutual friends and attachment to each other's families. When things started to go wrong, we convinced ourselves that getting married would sort us out. In fact, it was the worst thing we could have done." The commitment the couple had hoped would provide a fresh start just made them feel trapped. "In the end, we had to admit that we'd outgrown each other," says Howell. "Eighteen months after the wedding, Joe moved out."

Psychologist Susan Quilliam puts Howell's experience down to the phenomenon of the "Elastoplast Marriage". "If a couple are moving towards marriage from the start of the relationship, living together for a while beforehand won't trip them up. But when a couple who don't intend to marry suddenly decide to tie the knot, it's because something has changed or the relationship has hit problems. The problems are exacerbated by the strain of getting, and being, married."

If a couple are drifting apart or stuck in a rut, marriage can seem like a unifying project, something to work towards. "The process of getting married can provide a new sense of direction," says Quilliam. "The problem is that once you're married, there's nothing left to aim for, particularly if you've got children already." In other words, you've played your trump card and are left with no aces up your sleeve.

As well as the Elastoplast couple, wedding bells can equal alarm bells when it comes to the natural-born romantics in us. "After the buzz of the wedding and the planning, the marriage itself can feel a little flat," says Katie Knowles, whose two-year marriage broke up earlier this year. "Your partner has been this dashing groom, then suddenly he's slumped next to you on the sofa in his boxers, picking his teeth, and you think, 'Is this it?' You see each other in a different light once you're married."

Too right - suddenly the flicker of the scented candle has been replaced by the glare of the anglepoise lamp that your beloved is currently using to inspect his verruca. This is marriage, warts and all, and some people just can't handle it.