Demi Harris, 21, struck out after she had been pulled fully clothed into a hot tub - when angered by his antics in front of other women.
She was cleared of murder but found guilty of manslaughter by a jury at Nottingham Crown Court in October. She nodded and stood with her hands clasped as Judge Stuart Rafferty QC sent her to prison.
Harris shared a house with Christopher Pearson in Strathmore Close, Hucknall.
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She stabbed him with a knife he kept on his bedside table.
The judge said that Mr Pearson, 39, had been abusive towards Harris during their relationship.
“Mr Pearson, as we all are, was a man with flaws. Whether it came from insecurity, one doesn’t know.
“But undoubtedly he had treated you badly and inappropriately from time to time in your relationship.
“On a regular basis, he was abusive to you, either verbally or violently,” the judge told her.
On the night of the attack, both had been drinking before returning home with friends.
Harris decided she had “sufficient to drink” and left the party but later felt he was “behaving with friends in a jacuzzi in a way which you thought was inappropriate and of which you were undoubtedly annoyed,” the judge said.
Witnesses described her as “stomping around” and she turned off the electricity. Mr Pearson jumped naked from the hot tub in the garden and the pair clashed at the top of the stairs.
While he made threats and grabbed her hair, “he still struck you no blow,” said the judge who pointed out that she did not warn him that she had a knife. The fatal wound was to the aorta, the main artery, and hit the spine.
The judge added: “What happened on top of the stairs was in effect the final straw. You, finding yourself in possession of the knife, lost your temper and stabbed him.
“There is a history of violence and abuse by him towards you. Whether it is significant, it is difficult to judge.”
Harris will serve up to four years in custody and then four years on licence. The sentence will be reduced by 140 days to take account of her time in a prison immediately after being arrested and also while wearing an electronic tag as part of a curfew.
Sallie Bennett-Jenkins QC, defending, said the pair got together when Harris was 18 and it was her first serious relationship. They were planning to have children.
She told the judge: “There is a clear and marked history of significant violence towards Miss Harris.”
Harris had said: “I can’t understand any of this because I loved him.”
Miss Bennett-Jenkins said: “Mr Pearson was the person she lived with and loved. She has expressed remorse and utter horror of what has happened.
“She knows the impact on his family and friends and has a genuine heartfelt remorse.”
Prosecutor Michael Auty QC said Harris used the knife to inflict three injuries
He added: “The reality is that it was an utterly unnecessary death.”