The X-Factor judge Guy Sebastian and his wife have been to Waverley court, for the hearing of a man accused of trespassing at their home.
Jules Sebastian told the hearing she was frightened when she heard a stranger enter the property.
The celebrity couple had been called to give evidence against Matthew Jones, who’s accused of trespassing at their Clovelly home in May.
Jones' lawyer Winston Terracini says his client simply got lost on his way to a party.
But Jules Sebastian told the court she panicked when she saw him come through their gate late at night, as she was home alone with her baby, and she thought he looked to be on drugs.
The court heard Guy Sebastian came rushing home on his motorbike, and that he grabbed Jones and headbutted him with his helmet still on, breaking his two front teeth.
A triple zero call was played, in which Jules is heard saying to her husband.
“Don't do anything babe,” before the operator asks “what is your husband doing?”
Jules is then heard saying “oh my God!” The operator asks, “what happened?” Jules says to Guy, “Babe."
“What happened Ms Sebastian?” the operator repeats. “He hit him,” Jules replies.
In the witness box today Ms Sebastian denied Guy headbutted the young man, describing it as a “collision” of heads.
Jones' lawyer accused her of changing her story to protect her husband.
The case will return to court next week.