Murder accused Patrick Quirke called his former lover Mary Lowry a "right bitch" and warned her brother that he would personally remove her from church if she attended a mass for his son, who had died tragically.
Eddie Quigley, Ms Lowry's brother, also told the Central Criminal Court trial that Ms Lowry visited a psychic to see if it would help after her boyfriend Bobby 'Mr Moonlight' Ryan disappeared.
There was also evidence from acting State Pathologist Dr Michael Curtis that the most likely cause of the injuries that killed Mr Ryan was impact with a vehicle but that the pathology evidence was "sub-optimal".
Mr Quigley completed his evidence in the trial of Mr Quirke (50), of Breanshamore, Co Tipperary, yesterday.
Mr Quirke has pleaded not guilty to the murder of part-time DJ Mr Ryan, who went missing on June 3, 2011, after leaving his girlfriend Ms Lowry's home at about 6.30am.
His body was found in an underground run-off tank on the farm owned by Ms Lowry and leased by the accused at Fawnagowan, Tipperary, 22 months later in April 2013.
The prosecution claims Mr Quirke murdered Mr Ryan so he could rekindle an affair with Ms Lowry (52).
Mr Quigley told prosecution counsel Michael Bowman that following Mr Ryan's disappearance, Ms Lowry visited a psychic in Nenagh to "see if that could help in any way."
He also recalled building an extra bedroom on to her home for her eldest son Tommy, who had been sleeping in a room in his grandmother's granny flat attached to the house.
In August 2012, the Quirke family suffered the tragic loss of one of Mr Quirke's sons.
Some days after the funeral, Mr Quigley was working on the roof of Ms Lowry's house and overheard loud shouting between Mr Quirke and his sister.
A week or two after that, Mr Quigley was again at Ms Lowry's house when Mr Quirke approached.
"He said my sister was a right bitch and didn't support him or [Mr Quirke's wife] Imelda," the witness told Mr Bowman.
Mr Quigley said he responded: "Do you not think Mary has enough to deal with?"
Mr Quirke then told him he only wanted friends and family at his son's month's mind mass and would "personally remove her from the church".
Mr Quigley told him who attended the mass was up to Mr Quirke and Imelda.
The witness also referred to an incident where Mr Quirke talked about the deceased.
He "hadn't good things to say about Bobby Ryan", he said.
"Mr Quirke was trying to get across to me that Bobby Ryan was a DJ and the boys [Mary's sons] were being left alone," he added.
Mr Quirke was angry, he said, and further told him that Mr Ryan was involved in music and out late at night and "would be a man for the women".
He also remembered a family wedding in Spain which Ms Lowry was due to attend but she could not find her passport when it came time to go.
Mr Quigley said he helped to search for the passport but they did not find it and she was a couple of days late arriving in Spain.
In December 2012, she showed her brother CCTV footage of Mr Quirke looking in her doors and windows and, on another occasion, Mr Quigley was there when Mr Quirke returned a key to Ms Lowry.
Mr Quigley tried the key and found that it was for Ms Lowry's front door.
Following the recovery of Mr Ryan's body in April 2013, Mr Quigley saw Ms Lowry and she was "visibly upset".
They had a cup of tea and waited for her boys to finish school.
She and her children stayed with Mr Quigley in Newport, Co Tipperary, for a week, travelling to Fawnagowan to take her children to school.
That Friday the media called at Mr Quigley's house so Ms Lowry decided to stay at their sister's home and she later rented a house in nearby Dundrum.
Bernard Condon SC, for the defence, asked Mr Quigley if he had ever seen the tank where Mr Ryan's body was found prior to 2013.
The witness said he saw a trough around it but the tank was covered with top soil and mud, and he never saw any concrete and did not know of the tank.
The trial continues on Monday in front of Justice Eileen Creedon and a jury of six men and six women.