If you're a solo photographer at a wedding, normal morning plan is: go to groom's house first, watch the guys lazily roll out of bed and throw on suits, then go to bride's for last-minute frantic panic and chaos -- and then head to ceremony.
In summer especially, this can present grooms with a dilemma: "I have to go through with all this photo nonsense, but today is so fricking hot. Do I really have to put the suit on, mate?"
A common solution: fake it. Get changed for the photos, then change out into civilian clothing to lounge around comfortably for a few hours.... then jump back into the suit later.
Similarly, if you ever see footage of the groom "exiting the house to go to the church", there's a good chance that, in reality, he walks back into the house straight afterwards and grabs another beer.
