Civil partnerships introduce parity, both legally and publicly, between the status of a gay couple and that of a married couple. For some it is a step too far to consider that the gay couple married, while others see the civil partnership as a joyful example of the increasing tolerance of our society. Others see the civil partnership as a shameful capitulation to heterosexual norms.
Whatever your view, if you have been invited to celebrate a civil partnership, you should simply consider the feelings of the couple. If you are uncomfortable with the concept, don’t go – whatever your attitude, it is their day of celebration and they deserve the uncritical approval and happiness of those around them.
Likewise, if you are inviting friends and family to your own civil partnership, consider the guest list carefully: you may think your elderly uncle should be there, but if he’s going to be uncomfortable and awkward with your friends then perhaps he’s better left off. Once accepted, the etiquette surrounding such an occasion is determined largely by the couple themselves: they will tell you how closely they are conforming to a traditional wedding day, and whether you should dress in conventional garb, throw confetti, give wedding presents, and so on.