A Queensland woman feared her partner would burn down her home a second time when she found a Molotov cocktail he was making in the kitchen.
The "vicious and vindictive" 32-year-old man, who cannot be named for legal reasons, laughed while watching the woman's home burn in April 2017, a Brisbane court has heard.
After starting the fire in a back room, he told his partner she had 25 seconds to get out the house, which was so badly damaged it had to be knocked down.
The woman tried to douse the blaze with jugs of water but was forced outside by smoke and fire, Judge Elizabeth Wilson told the Queensland Supreme Court on Wednesday.
Witnesses said the man laughed as the house burned and said his partner had got what she deserved.
When police told the man to look at what he had done to his partner's cat which was burnt in the fire, the man said "I love it" and laughed.
The cat's injuries were so bad the animal had to be put down.
During his arrest the man said "boom" while playing with a lighter, tried to use the police radio, grabbed one officer's Taser and headbutted another while being put into a police van.
Four months later, the couple were back in a relationship when he threatened her with two large knives.
The man was on bail for the previous arson during the "terrifying" incident in which he asked whether she wanted to die fast or slowly, Judge Wilson said.
He started to make the Molotov cocktail in the kitchen but abandoned it.
He hit the side of her head with a 30cm steak knife, causing a superficial two centimetre-long cut.
Judge Wilson said the man was "vicious and vindictive" to the woman, who was in court to support him.
She had visited him while he was in custody for more than two years.
"Your partner showed you the safe haven of her house and you responded by stabbing her," Judge Wilson said.
The court heard the man had drug-induced psychosis and acted violently towards his partner when using drugs.
"You do accept that there is a connection between your drug use and your violence," Judge Wilson told the man.
The judge sentenced him to four years in jail, which was wholly suspended, after he pleaded guilty to arson, wounding and serious assault.
He is expected to be released from custody on Friday.