A teenager kicked in his female housemate's bedroom door and attacked her, dislocating her finger and splitting her lip.

Kurt Faries, 19, pleaded guilty to assault causing actual bodily harm, but he denied reports that he repeatedly punched her during last month's attack.

Asked why he attacked her at all, Faries told Magistrates' Court she had insulted his mother in the August 12 incident.

Crown counsel Kristy-Ann Keillor said Camilla Johnson arrived at the home around 5.30 p.m. and complained that some household chores had not been done.

The two began to argue. At some point Ms Johnson turned and went into her room and closed the door.

Faries kicked down the door and repeatedly punched Ms Johnson in her head and body, Ms Keillor said.

He continued to punch her, dislocating her ring finger in the process.

Ms Johnson also suffered a split lip and bruising to her face and body.

Yesterday Faries admitted kicking in his housemate's door, but denied hitting her.

"I kicked in the door and the door hit her twice," he said. "I grabbed her by the shirt and I yelled at her. I didn't roll up my fist or nothing."

Asked by Senior Magistrate Archibald Warner why he attacked Ms Johnson, Faries said: "She called my mother a whore."

Mr. Warner adjourned sentencing until November 24 so that a Social Inquiry Report could be carried out.

He released Faries on $2,000 bail with a surety under the condition that he does not interfere with Ms Johnson.