We are having a very small wedding with only 50 people that we know very well. I inivted a couple and only one spouse can attend. The attending spouse emailed me to ask if they can bring a friend to take the place of their spouse. I understand why they want company, but I feel odd having a total stranger at this small and intimate wedding. To be clear the invitation was addressed to Mr. and Mrs. XYZ and it did not read Mrs. X and Guest. I would rather invite another close friend now that there is an open space because I want to be surrounded by people we know and love.
What should I do?