It is an adaptation of the 1958 novel of the same name by Alan Sillitoe, who also wrote the screenplay adaptation.

After recovering, Arthur returns to work, and realises his affair with Brenda is finished after her husband tells him to stay away from Brenda.
Challenged to a drinking contest, Arthur defeats "Loudmouth" before falling down the stairs drunk.

Sillitoe later wrote three further parts to the Seatons' story, https://en.wikipedia.org/w/index.php?title=Saturday_Night_and_Sunday_Morning&oldid=946399068It was adapted by Sillitoe into a 1960 film starring During another night out at the pub, Arthur meets Doreen, a young unmarried girl with whom he begins a relatively innocent courtship — all the while keeping Brenda and Winnie a secret.

However, although Jack is oblivious to his wife's infidelity, Winnie's husband Bill catches on — and Arthur's actions catch up with him when Bill and an accomplice jump Arthur one night, leaving him beaten and bed-ridden for days. Arthur Seaton is 21 years old, and enjoying a night out with Brenda, the wife of a colleague at work.

1989 - Equally remarkable, though for different reasons, is Alan Sillitoe's new novel, The Open Door. Made in 1960, it was groundbreaking in both its portrayal of the industrial nightmare of working class factory life, and its unrepentant, cocky anti-hero Arthur Seaton.

With Albert Finney, Shirley Anne Field, Rachel Roberts, Hylda Baker.

When Doreen comes to check up on him, Arthur finally comes clean about his affairs with Brenda and Winnie. inspired the song ""Saturday Night Sunday Morning" is the title of a song from Dr. Strangelove or: How I Learned to Stop Worrying and Love the BombThe film is the origin for the title of the debut album of indie rock band Much of the exterior location filming was shot in Original British quad format cinema posterThe closing scenes show Arthur and Doreen on a grassy slope overlooking a housing estate with new construction going on. Saturday Night and Sunday Morning is a classic social realist film of the British New Wave. At the same time, Arthur carries on with Brenda's sister Winnie.

"Saturday Night and Sunday Morning (1960) - IMDb"The Contemporary Review - Volume 254 - Page 213

By the end of the novel, Arthur and Doreen have made plans to marry. Saturday Night and Sunday Morning holds one principally as the portrait of a dimly dawning conscience, a boy-into-man metamorphosis too consistently honest to permit false ironies or heroics.

A rebellious, hard-living factory worker juggles relationships with two women, one of whom is married to another man but pregnant with his child. The film ends with Arthur and Doreen discussing the prospect of a new home together, with Arthur showing that he still has mixed feelings about settling down into domestic life. He also begins a more traditional relationship with Doreen, a beautiful single woman closer to his age. Doreen, who lives with her mother and aspires to be married, avoids Arthur's sexual advances, so he continues to see Brenda as a sexual outlet. The film went £3,500 over budget and two days over schedule when filming at a Nottingham factory proved more difficult than expected.Most Promising Newcomer to Leading Film RolesAfter Doreen complains about not going anywhere public with Arthur, he takes her to the "Saturday Night and Sunday Morning (1960)"Arthur spends a week recovering and is visited by Doreen; they later have sex. "SATURDAY NIGHT AND SUNDAY MORNING with Ian McKellen"Whatever People Say I Am, That's What I'm Not"100 'most inspiring' novels revealed by BBC Arts"Arthur works at a lathe at a bicycle factory with his friend Jack. Saturday Night and Sunday Morning is a 1960 British Kitchen sink drama film directed by Karel Reisz and produced by Tony Richardson.
Sunday Morning follows the course of events after Arthur's assault. It is the third and final volume of the Seaton trilogy, the other two being Saturday Night and Sunday Morning and Key to the Door. Arthur enjoys breakfast with Brenda before her husband Jack gets home from a weekend at the races.