The Central Criminal Court has been told Richard Satchwell was controlling and odd with his wife, Tina.
Ms Satchwell's half-sister, Lorraine Howard, said Mr Satchwell was obsessed with his wife.
She said Ms Satchwell had a temper, but she had never once seen violence from her.
Ms Howard was the only witness for the defence in the trial of Mr Satchwell, 58, who pleaded not guilty to murdering his 45-year-old wife in March 2017.
Closing speeches in the case are due to begin tomorrow.
Ms Howard told the court she and Tina were half-sisters and had the same mother.
Ms Satchwell was raised by her grandmother and for a long time, Ms Howard said Ms Satchwell thought she was her aunt.
She said Ms Satchwell found out the truth at the time of her confirmation when she went looking for her birth certificate. Ms Howard said her half-sister was in shock and felt she had been lied to for a long period of her life.
Ms Howard told defence counsel, Brendan Grehan, that their relationship changed when Ms Satchwell became aware that they were half-sisters, and not aunt and niece.
She said Ms Satchwell felt resentment and hurt that she was given away by their mother and that Ms Howard was kept, adding it caused big distress for Ms Satchwell and sometimes Ms Howard bore the brunt of that.
Ms Howard said they would be friends for years and then would fall out - nearly always about the same issue because Ms Satchwell felt "somewhat abandoned".
Ms Howard was asked what she thought of the relationship between Ms Satchwell and her husband. She said Mr Satchwell used to call Ms Satchwell his "trophy wife" or "trophy girlfriend".
Ms Howard said she did not like it and did not think it was right to refer to someone as a trophy.
She described Mr Satchwell as obsessive, wanting to know where his wife was all the time, who she was speaking to all the time and where she was going all the time.
She said every friend Ms Satchwell ever met, he would find fault with them, until Ms Satchwell’s circle of friends became smaller and smaller.
"I didn’t like the way he was with her," she said, adding: "I thought it was controlling and just odd."
Ms Howard was asked about a statement she made to gardaí in August 2020. She said she gave the statement in hurt and anger.
At the time, Ms Howard said she believed Ms Satchwell to be alive and was angry that she was putting her family through stress.
She said she believed Ms Satchwell had taken money and Mr Satchwell had described her as being a violent person.
Ms Howard said she blamed her half-sister for putting their family through more stress when she said Mr Satchwell was the person she should have aimed this anger at.
She agreed she had told gardaí in 2020 that Ms Satchwell "wore the trousers" in the relationship and that Mr Satchwell knew she was above his league.
She said he spent every penny on his wife to dress her up and agreed she had used the phrase "high maintenance" to describe her half-sister.
She said he was happy with just the two of them.
'Definitely possessive'
Ms Howard was asked by gardaí in 2020 if she was concerned that Ms Satchwell was depressed, she said she had concerns because of matters that had happened in her own family and that Mr Satchwell was trying to portray his wife as being depressed.
She said she came to the conclusion that maybe there was some kind of mental health issue that would explain the person he was describing.
She said before Ms Satchwell went missing, Mr Satchwell had never once described her as violent or aggressive and now suddenly he was saying she was violent and had caused all kinds of damage to his person.
She said he showed her every scar on his body and blamed his wife for it.
Ms Howard said that was why she was concerned about her mental health as she said she felt "this is not Tina".
She said at the time she would not say Mr Satchwell was controlling of his wife, but she said he was "definitely possessive".
However, Ms Howard said she had since changed her opinion based on information she had received.
Ms Howard said she had described Ms Satchwell as having a "Jekyll and Hyde" personality because of their own relationship where they would sometimes be friends and sometimes would not be.
She said they both had tempers and she agreed she had told gardaí that Ms Satchwell had a "vicious temper".
But she said she had never seen violence from Ms Satchwell, adding they had many arguments and Ms Satchwell had never once put a hand towards her.
She said she had once seen scratches on Mr Satchwell’s back, but she said he never said Ms Satchwell gave him the scratches.
He worked in buildings she told the court, as did her own husband and he too was always covered in scratches.
Ms Howard also said she had walked in on a conversation when she was a teenager, between Ms Satchwell and her grandmother, in which Ms Satchwell was laughing and said she had slapped Mr Satchwell on the face.
However she said she did not hear the start or end of that conversation.
Ms Howard agreed she was asked by gardaí about Mr Satchwell’s claim that his wife had told him she would call the guards on him, if she ever left him and he tried to find her.
Ms Howard told the court Ms Satchwell knew she could not get away from her husband – that he would follow her to the ends of the earth.
Ms Howard agreed she had not been in contact with Ms Satchwell for 15 years before her disappearance because of an incident in the family which had caused a divide.
She said when the family got Ms Satchwell’s remains back, she was buried in two graves – half of her ashes were put with their grandmother, who had reared Ms Satchwell, and half were put with their brother who died in 2012.
