There is no etiquette for attending a same sex wedding. However, there are "rules" that you should follow to be respectful and not offend the couple. - You should not bring up any personal or religious views about marriage during the ceremony or reception, especially if you are not invited to the wedding. - You should wear appropriate clothing for the occasion, but not wear anything that would make anyone uncomfortable. - You should be careful with your words and actions during the ceremony and reception. - If you have any questions about what is appropriate behavior, ask before attending.