Is there a common "rule" as to single guests bringing dates to weddings? We are going to easily have about 200-215 guests and a huge bridal party. My fiance and I (who will be paying for this on our own) decided this weekend, that dates were a "no". But I had a groomsman make a comment about "needing to find a date before next year" (he is forever single, so this would likely never be an actual girlfriend...even in a year) and I suddenly felt bad.
Is there a standard rule or is this completely up to us? How do we make this known without sounding rude?