As a wedding photographer it is crucial that not only do we behave professionally at all times, but that we are able to persuade the guests to go where we want them, and pose how we want them to (no glowering at the camera because they've had an argument with Great Aunt Nellie!). To be able to achieve that, we have to be comfortable talking to anyone, whatever mood they are in, and weddings are traditionally a time of heightened moods! Not only are the newly married couple ecstatically happy, and not only may their families be meeting each other for the first time, also certain members of each family may be seeing each other for the first time in a long time. Possibly even since the last family wedding, or even worse, since a family feud. While people generally come together for weddings, those underlying feelings are still there, and after a few drinks, they can burst out.
Nowadays, with many families having become extended due to divorce and remarriage, tensions can run even higher, particularly because it is not always possible to give everyone a role in the wedding that they feel they deserve. As you are the bride and groom, your opinions are the ones that matter, and chances are you will want to involve the people who spent most of the time bringing you up, whether that is a natural or a step-parent. As you will probably also want the other parents who you are not as close as to attend your wedding and celebrate with you, you may find that they may not be as gracious as you would like!
This is where you want to use those bridesmaids and ushers. Warn them in advance of any family issues, and make sure they are aware that it is their responsibility to ensure you don't notice any trouble! They can tell you about it after you have returned from your honeymoon and you can all laugh about the silliness of it! Your bridesmaids and ushers can help your wedding photographers with the diplomacy required to make sure that any wayward guests still appear where they should, when they should, and any potential disruption is avoided. It is your wedding photographers' responsibility to do everything they can to get a fantastic selection of wedding photos for you, but if you know your family are likely to be difficult, it is helpful to warn them! And perhaps ensure that the people least likely to get on are only in the bare minimum of posed photos together!