The line "Never rat on your friends, and keep your mouth shut" is from the 1990 film Goodfellas, directed by Martin Scorsese.
Goodfellas is a 1990 American crime film directed by Martin Scorsese. The film stars Robert De Niro, Joe Pesci, and Ray Liotta as three mobsters in the 1950s and 1960s. The famous line "Never rat on your friends, and keep your mouth shut" is delivered by Joe Pesci's character, Tommy DeVito. The film was a critical and commercial success, and was nominated for six Academy Awards, including Best Picture. It is widely regarded as one of Scorsese's greatest films.