Lee Barber accused the woman of cheating on him and hurled a blue recycling bin at her car, then reached through the window and grabbed her by the hair, after a night out on July 18.
"He then took hold of her right index finger as she shouted at him to stop, and bent it back," prosecutor Stephanie Hollis told Sheffield Crown Court, on Thursday.
She explained how Barner met the woman, who was a friend of his mother's, in 2010, but their relationship had been "marred with violence."
"He assaulted her in 2013," said Ms Hollis. "However, she resumed the relationship, but it broke down and there was further violence.
"She withdrew her support for the prosecution and he was dealt with for affray."
The court heard how Barber smashed a glass into a woman's face, causing lacerations, in a pub beer garden, in January 2017, for which he received a 22 month sentence, suspended for two years.
But he breached the order in January 2018 when he punched a pub manager in the face, added Ms Hollis.
Barber, aged 37, of Northern Avenue, Arbourthorne, pleaded guilty to assault occasioning actual bodily harm and criminal damage at the earliest opportunity.
Zaiban Alam, mitigating, said Barber sustained a "moderately traumatic brain injury" in 2006 which caused epilepsy and he suffers from regular seizures.
"It is no coincidence that his first conviction was in 2007," she said.
"His father acts as his carer since the death of his mother. Prior to the injury he was in a successful relationship - that ended a short time afterwards.
"He has sadly no contact with his two children.
"Prison has been very difficult for him. He has been remanded since October 28, and has served the equivalent of two months while on remand.
"This is not a pattern of violence against women. He tells me this relationship is finally at an end."
He was jailed for a total of 30 weeks.