The invitation clearly identified two as the number of invited guests.
What you describe is a fairly common occurrence. Most wedding guest lists end up, believe it or not, with a few additional names added by guests themselves!
First of all, it’s important to understand that – as frustrating as it may be – most often when this happens it is an innocent mistake on the part of the responding guests. Although it may appear somewhat ignorant to add an additional name to the response card, this happens at many weddings due to a common misconception on the part of many guests; many people mistakenly believe that because it is up to them to fill in the response card with the number of guests attending, they are ‘allowed’ to include an additional guest or two, should they feel it appropriate. They do this, intending no harm, often entirely unaware that this is any form of social blunder.
You should also know that most individuals who do this are not looking for a free meal for the guest – they usually, and often very generously, provide enough of a wedding gift to more than adequately cover the guest’s meal as well as a gift from the additional guest.
So now the question becomes: does the fact that they have included this additional person present a real problem, or is it merely a matter of being irksome? If, for example, you are already filled to capacity and cannot squeeze in another guest, this is clearly a problem and measures will have to be taken. On the other hand, if it is simply a matter of an annoyance, etiquette would suggest that you take the most gracious and congenial approach and grin and bear it, remembering that any violation of etiquette which the guest has made in committing this blunder was almost undoubtedly unintentional.
This is the approach which is likely to cause the least amount of uncomfortable feelings or embarrassment for either you or the guests, although some embarrassment on the part of the guest may be unavoidable.
Nobody ever said hosting a wedding would be easy, but as you beam with pride on your daughter’s wedding day, you will discover that it is all well worth it in the end!