Isn't a wedding a time to uphold the vows of the two people getting married. If they have chosen to live a life that abstains from alcohol, shouldn't your part in the wedding be to support their decision, and not think of yourself, and your own selfish desires to drink at the wedding because afterall isn't a wedding all about drinking? No, it is about honoring the vows of the people who you love who are getting married, and in that honoring their wishes to uphold their desire to honor God, and not drink at the wedding.