Raymond Hodgson, 31, was charged with common assault after being appalled to discover that his partner of five years, Emma McCormick, had been reading the racy book.
Carlisle Magistrates' Court heard how their tiff over the book escalated to the point where Hodgson, from Carlisle, Cumbria, decided take to his revenge.
In court, Hodgson pleaded guilty to the single charge of common assault.
Prosecutor Adrienne Harris said the couple began arguing on June 25 after McCormick began reading extracts from the best-selling novel by E L James - now the fastest selling book of the year.
The pair had been in a relationship for four or five years, though both still live with their respective parents.
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Miss Harris said: "Mr Hodgson thought that the book was pornographic, and that she should not read such literature.
"The argument continued into the following day, with the two exchanging text messages."
That conversation, which included some discussion of private family issues, left Hodgson feeling angry.
Mrs Harris said: "He went to her home at 7pm on June 26 and took with him a bottle of brown sauce.
"She answered the door and the argument continued.
"She went to close the door and he jammed his foot into the door, slapped her once in the face, and then squirted her with this bottle of sauce."
When interviewed by the police, Hodgson said he felt Fifty Shades of Grey was a 'distasteful' and 'pornographic' book.
Miss Harris said: "He said he had every intention of squirting sauce over Miss McCormick, but he now regrets having done this, realising how stupid it sounds.
"He didn't realise that the sauce incident would be classed as an assault. He is sorry for his actions."
Malcolm Dodds, defending, said his client denies slapping Emma McCormick.
He named the book the couple fell out over 'Fifty Shades of Grey.'
Mr Dodds said: "He lost his temper and went round to her home armed with a bottle of brown sauce, which he should never have done.
"Emma says it stung her eyes and it was all over the walls, which she had to clean up afterwards. I've spoken to Raymond and he's extremely sorry about it.
"He was angry that she suggested he slapped her because he hadn't. But they are now friends and they have been in touch with each other."
Passing sentence, District Judge Gerald Chalk said Hodgson's actions had clearly been intended to demean Miss McCormick.
He ordered that he should pay his victim £100 compensation and £85 towards prosecution costs.
The judge also imposed a 6pm to 8am curfew for the next six weeks and a six-month community order.
Asked about his views of the book after the case, Hodgson said he thought Fifty Shades of Grey was 'wrong'.
He said that he did what he did to Miss McCormick to show her what saucy really meant.