The role of Olivia was originally written for London actress Emilia Clarke, but Clarke's agent explained that she was too busy with various projects such as Game of Thrones.
At one point, the director tried to get hold of Neil Maskell for the role of Ben.
The embarrassing story told by Fiona about Matt as a little boy wanting to try on a bride's dress actually happened to director Kris Smith when he was 7 years old. The bride's dress story is something Kris Smith is embarrassed about however he added it in the script explaining that it would generally be something that Matt would find horrifying to think back to.
In the first draft of the script there was another character that was eventually deleted weeks before the shooting began. He was going to be Matt's housemate Todd, someone he knew since school.
The role of Rebecca was written with Sally Carman in mind.