Content is currently unavailable. Both links give the same message. At least it didn’t show me my own page.
I have heard other photographers complain about this. Some have something in their contracts, but if you and the bride have a contract, it is not binding on me, the guest, as I am not party to the contract. Stressing the bride about her guests photographing over your shoulder may have the effect that all her friends choose a different photographer for their weddings.
Sometimes, the bridal party are taken to a venue between church and reception, there the photographer has the party to themselves for some period of time. Then there is the question of when to get shots of family and guests.
This is probably the discussion to bring up the opportunity you have as a professional to have an assistant plus more and better equipment. For instance, you can pose them with a bright sky behind them and light them with your flash, ideally perhaps an off camera flash with modifiers. You get a nice well lit photo, the guy behind you with a point & shoot gets silhouettes. Done well, it can be an opportunity to demonstrate the benefits of hiring a professional instead of “Uncle Fred” as a local pro refers to members of the point & shoot crowd.