The woman at the centre of a murder trial has given evidence in the Supreme Court in Launceston today.
Crystal Wells' partner Darren Booth was allegedly stabbed to death by her ex-boyfriend at her Kings Meadows home in May last year.
Michael Vernon Lowe, 52, of Waverley has pleaded not guilty to murder on the basis of self-defence.
Ms Wells told the court that Mr Lowe had reacted poorly to her request that they split in the lead up to the alleged murder.
``(He said) he was going to harm himself, if he could not have me,'' she said.
On one occasion Mr Lowe showed up at her door, forced his way in and confronted Mr Booth and another person in the home.
Mr Lowe said he didn't have a problem with them only ``whoever's with Crystal'', she said.
Afterwards he sent a text message to her claiming he'd ``find out an address for (Mr Booth ) and he'll be hurt,'' she said.
Ms Wells will be cross-examined by defence counsel Greg Richardson later today.