The division between "people who wanted to go to the ceremony and are miffed that they only got invited to the evening event" and "people who are really happy they got invited to only the evening event because wedding ceremonies are dull as ditch water" clearly delineates the REAL two genders.
Evening Do only invites for weddings are such bullshit. "Oh, please come to the after-party for the event you didn't make the cut for. And bring us, the people who had £20k spare to do this, a present off this special list as well. It would mean _so_ much to us!"