According to Jamie Dornan, there was a lot of goofing off simply because it’s weird to think about fake marrying somebody, especially when things like vows are being filmed.
The wedding sequence isn’t a huge portion of Fifty Shades Freed.
In the Blu-ray extras, other series lead Dakota Johnson also mentions how strange it was to be wearing a wedding dress, as she’s unmarried in her regular life, so that aspect definitely came into play, as well.
Still it’s a nice way to give fans of the books and the movie series an actual idea of what a wedding between Christian Grey and Anastasia Steele would look like, which includes a beautiful Pacific Northwest-looking space and a slew of cool crystal chandeliers that were imported to the set.