Because the film's PG-13 rating was originally an "R," Rebel Wilson had to go out and argue with the board that the film was no raunchier than similar comedies that had received PG-13 ratings.
Rebel Wilson loved the Riviera home that was created for Anne Hathaway's character so much that she bought a lot of the furniture after production was over.
Anne Hathaway said in an interview on Good Morning America (aired on 5/7/19) that she avoided performing a traditional English accent for this film. She said that audiences know she's American and could potentially scoff at her numerous English characters. So, because her character Josephine is a con artist, Hathaway performed as if maybe Josephine is not actually English at all but speaks in an English accent as another con.
On the Stephen Colbert show Anne Hathaway revealed that her ad lib line "Well that was unexpected" was based on a time when her father was given the wrong medicine and had to sleep it off in her apartment. He slipped and fell in the bathroom and hit his head. While she was alarmed and asking if he was all right, said "Well that was unexpected."
When Thomas addresses the man at the bar (William Brand), the man replies in Dutch "You're cute. Your room or mine?" Thomas confuses Dutch with German until he is corrected by Josephine (who tells the Dutchman "This young man isn't interested in sex with you"). This may be a jab at the fact that Dutch in Hollywood films is often substituted for German, which is in the same language family but still a very different language. This is one of the rare instances where proper Dutch is spoken. Even Anne Hathaway does a decent attempt.
Alex Gaumond: as a waiter on the train featured at the beginning of the official movie trailer. Gaumond is an Olivier Award nominated actor who starred in the stage adaptation of "Dirty Rotten Scoundrels" at the Savoy Theatre, in London's West End. In the stage production, he starred opposite Robert Lindsay and played the role of Freddy Benson, which was played by Steve Martin in Dirty Rotten Scoundrels (1988), and by Rebel Wilson in this remake.