At a certain point the narrator hypothesizes how many combinations there can be in an 8-seat table. They are 5040
Sam Claflin and Eleanor Tomlinson played brother and sister 10 years previous in The Lost Future (2010).
Aisling Bea (Rebecca) has worked with Jack Farthing's (Marc) real-life girlfriend, Hanako Footman in an episode of the TV show, The Town (2012). They played Carly and Isabella respectively. The episode in question is, Episode #1.2 (2012).