Write a summary of the text below, including the most important points, using your own words whenever possible (maximum 50 words).

As today's bride and groom celebrate their wedding, they have every excuse for being nervous. They exchange promises of lifelong fidelity and mutual support. However, all around them, they can see that many people do not and cannot keep these promises. Their own marriage has a one in three chance of divorce, if present tendencies continue.

Traditional marriage is facing a crisis, at least in Britain. Not only are there more and more divorces, but the number of marriages is falling. Living together is more popular than before. The family is now no longer one man, one woman and their children. Instead, there are more and more families which include parents, half sisters and brothers, or even only one parent on her / his own.

Although Britain is still conservative in its attitudes to marriage compared with other countries such as the USA, Sweden and Denmark, the future will probably see many more people living together before marriage - and more divorce. Interestingly, it is women rather than men who apply for divorce. Seven out of ten divorces are given to the wife. Also, one of the main reasons for divorce, chosen by ten times more women than men, is unreasonable or cruel behaviour. Perhaps this means that women will tolerate less than they used to.