Ben Roberts-Smith has denied demanding his mistress video herself taking a pregnancy test after she told him she was going to have their child.
Australia's most decorated soldier said he doubted the woman, known as Person 17, was pregnant during what he says was a period of separation from his wife Emma.
Nicholas Owens SC for Nine put it to Mr Roberts-Smith that after Person 17 told him she was pregnant in February 2018 he demanded she prove she was going to have their child.
Mr Roberts-Smith said he doubted Person 17 was pregnant but he had never insisted on proof by demanding she video herself taking a test.
Ben Roberts-Smith denied demanding his mistress video herself taking a pregnancy test after she told him she was going to have their child
'I'd just tried to end the relationship and she said she was pregnant,' Mr Roberts-Smith told the court. 'I was just sceptical of it.
'I didn't like the timing of it. It just didn't make sense to me.
'I believe I was being manipulated for a number of reasons.'
Mr Roberts-Smith said Person 17 had sent him an image of a positive pregnancy test but that had not proved anything to him.
'They're very easy to fake, pregnancy tests,' he told the court.
Mr Roberts-Smith also denied having assaulted Person 17 at Canberra's Realm Hotel after a March 2018 function at Parliament House.
'I have never hit a woman,' he said. 'I never would and I certainly never hit Person 17.'
Nine alleges Mr Roberts-Smith punched Person 17 in the temple because he was angry she had exposed their affair.
Australia's most decorated soldier, Ben Roberts-Smith, has denied punching a woman with whom he was having an affair in the face after a Parliament House function in 2018. He is pictured with ex-wife Emma Roberts and their children
Ben Roberts-Smith is suing three newspapers including The Sydney Morning Herald over claims he is a war criminal, bullied comrades and punched a woman in the face
He says she got drunk and fell down a set of stairs, seriously injuring her head, and that he cared for her when they returned to the hotel room.
Mr Roberts-Smith agreed he had taken photographs of Person 17 with an ice pack on her face but denied taking pictures of her naked body while she slept in their bed.
'No, and that's disgusting,' he said. 'I have never done anything like that and never would.'
He further denied waking Person 17 to have sex with her that night, or that she kept apologising for her behaviour at Parliament House.
'We didn't speak and we certainly didn't have sex,' he said.
Mr Owens repeatedly put it to Mr Roberts-Smith that he had not been separated from his wife while he was having an affair with Person 17 and he denied it every time.
'Emma and I discussed we needed some space apart because we did not feel connected to each other anymore,' he said.
Mr Roberts-Smith said that during the couple's 'amicable' separation he had sometimes stayed with friends but often spent weekends in a granny flat downstairs at the marital home.
He did not believe they had shared a bed during the separation but could not definitively say if they had ever been intimate.
Mr Owens: 'Did you have sex with your wife?'
Mr Roberts-Smith: 'I don't recall. Possibly.'
Mr Roberts-Smith and his new girlfriend Sarah Matulin attended the Magic Millions together on the Queensland Gold Coast in January this year. His ex-wife Emma Roberts is due to give evidence against him in his defamation case against Nine newspapers
The court has previously heard Mr Roberts-Smith hired a private investigator to follow his mistress to hospital after she told him she was going to abort their child.
He said he had not believed the woman was pregnant and so asked John McLeod to film her attending a Brisbane abortion clinic.
'It became evident that she certainly had not had a procedure that day,' he said.
Mr Roberts-Smith said he confronted Person 17 and she said she had undergone an abortion in Townsville, then that she had miscarried.
She later admitted she had made up the abortion story because she did not want him to leave her.
Mr Roberts-Smith said he had separated from his wife Emma at the end of September 2017 and met Person 17 the next month.
Mr Roberts Smith said he had not initially told his wife about the relationship with Person 17 and did not make their separation public.
The break had been amicable; Mrs Roberts continued to help with her husband's public speaking business and he had at first stayed in 'separate quarters' within their family home.
On Boxing Day that year Mr Roberts-Smith received a telephone call from Person 17's husband saying she and their children would be better off with him.
'It was quite a bizarre phone call,' Mr Roberts-Smith told the court.
Mr Roberts-Smith did not tell his wife about the relationship until they travelled to Singapore with their two children in January 2018 to see if they could work through issues which had plagued their marriage since 2015.
'The problem, from my perspective, was that I had not told my wife that I had started a relationship with Person 17,' he told the court. 'She did not know that and nor did I think that I was entitled to have a relationship with Person 17.
'In the interests of trying to move forward and have any hope of successfully maintaining our relationship, I decided I needed to tell her.'
The couple's separation continued after that trip but the pair felt they wanted to keep trying to make their marriage work.
Mr Roberts-Smith's ex-wife Emma has 'flipped' and is giving evidence for Nine Entertainment. The former couple is pictured together at a reception to celebrate military and civilian heroes in London in 2012
John McLeod, a former bodyguard to drug smuggler Schapelle Corby, produced video taken at a Brisbane hospital which convinced Mr Roberts-Smith that Person 17 had not had an abortion
'It certainly wasn't the end of our relationship,' Mr Roberts-Smith told the court.
In February, Person 17 and her husband had travelled to London with their children, and Mr Roberts-Smith broke off the affair.
From there, she messaged the former soldier to say 'the world would be better off without her - I didn't have to worry about her anymore.'
'It was clearly meant to be letting me know she was potentially going to self-harm,' Mr Roberts-Smith said.
Person 17 then went missing for 24 hours and did not answer texts or calls.
Mr Roberts-Smith later received a text message from Person 17's husband. 'In substance, he said I was supposed to look after her and I'd stuffed up, so I had better hope she comes home.'
After Person 17 had been missing more than a day she rang Mr Roberts-Smith to say she was hurt. He said she should go home because her family cared about her and needed her in their life.
What we know about Ben Roberts-Smith and the 'trial of the century'
Ben Roberts-Smith is suing Nine-owned newspapers The Sydney Morning Herald and The Age, plus The Canberra Times over allegations he committed battlefield crimes including murder.
His case, being heard in the Federal Court in Sydney, is expected to last ten weeks and is being bankrolled by his employer, the Seven Network's billionaire owner Kerry Stokes.
Mr Roberts-Smith served six operational tours in Afghanistan with the elite Special Air Service and left the regular army in 2013 with the rank of corporal.
He was awarded the Victoria Cross for actions at Tizak in June 2010 and the Medal for Gallantry for an earlier battle near the Chora Pass in May 2006.
The newspapers will plead that Mr Roberts-Smith was complicit in and responsible for the murders of six people in Afghanistan, and that those actions constituted war crimes.
Nine alleges Mr Roberts-Smith killed insurgents who had been captured and none of the killings was the result of decisions made in the heat of battle.
Mr Roberts-Smith has also been accused of bullying other SAS troopers and punching a woman in the face at a Parliament House function in 2018, which he denies.
The 42-year-old says some of his onetime colleagues who are making allegations against him are jealous of his feats of soldiering and are telling lies.
He is the first witness to give evidence. His testimony will be followed by what is likely to be a week of cross-examination by lawyers for Nine.
Character witnesses will then testify on his behalf, followed by witnesses for the newspapers.
Mr Robert-Smith's ex-wife Emma Roberts, the mother of his two children, is expected to give evidence for the publisher after 'flipping' sides.
Ms Roberts' friend Danielle Scott, John McLeod - a former bodyguard of drug smuggler Schapelle Corby - alleged Afghani eye-witnesses and 21 serving and former SAS members will also be called by Nine.
Mr Roberts-Smith's team will then call evidence from his other witnesses, including former SAS comrades.
Later in February back in Australia Person 17 called Mr Roberts-Smith to say she needed to see him about a serious matter.
Asked why they need to meet face-to-face Person 17 texted to say she was pregnant and in the coming days they agreed she should have an abortion.
Mr Roberts-Smith did not believe she was pregnant and asked Mr McLeod, who he knew as a private investigator, to follow her to a termination appointment.
'I just wanted to know the truth,' Roberts-Smith told the court. 'I felt that I was about to be manipulated and didn't feel the situation that was transpiring was real.'
Mr McLeod, a former bodyguard to drug smuggler Schapelle Corby, produced video taken at the hospital that convinced Mr Roberts-Smith that Person 17 had not had an abortion.
'She walked out the front and was able to pick up her own bag, looked normal as if she had just stepped out of her workplace or off a plane. Was dressed nicely, no issues at all.'
Mr Roberts-Smith is pictured shaking hands with the Queen at Buckingham Palace at a reception for the Victoria Cross and George Cross Association in 2018
The former soldier has taken leave as general manager of Seven's Queensland operations for the duration of the hearing
Mr Roberts-Smith later showed Person 17 the video and she claimed to have had an abortion in Townsville, then that she had miscarried. 'So now I had three stories as to what was actually going on,' he told the court.
Mr Roberts-Smith was concerned about Person's 17 wellbeing and felt he was being manipulated to maintain the relationship, which he tried, but it did not last.
Together they attended a function hosted by then prime minister Malcolm Turnbull at Parliament House on March 28, 2018.
The court heard Person 17 became so intoxicated at the function she fell down a set of stairs leading to an underground car park and suffered serious injuries to her face.
Mr Roberts-Smith said the night of the Parliament House fall spelt the end of his relationship with Person 17, who had apologised for her conduct.
'It effectively was the final straw,' he said.
The formal break-up was done over dinner in early April and a final night together in a hotel near Brisbane Airport.
Mr Roberts-Smith is also suing his ex-wife Emma Roberts, claiming she broke into his email account. She is pictured outside her Brisbane home on Friday
Mr Roberts-Smith was awarded the Victoria Cross for 'selfless' actions in Afghanistan and will now fight for his reputation in the Federal Court, claiming he was smeared by media giant Nine Entertainment
Nine newspapers later published a story claiming Mr Roberts-Smith had argued with Person 17 at the Realm Hotel after the function and was angry because he feared she had exposed their affair.
The papers claim that in response to Person 17 saying, 'My head hurts', Mr Roberts-Smith had said, 'It's going to hurt more' or 'I'll show you what hurt is' and punched her in the left eye.
Barrister Bruce McClintock SC for Mr Roberts-Smith has said the woman made no allegation of assault against his client until after he ended their relationship.
Mr McClintock asked Mr Roberts-Smith how he felt about being accused of domestic violence by the newspapers.
'That particular allegation, I feel, combined with being called a war criminal, has ruined my life,' he said.
'For a long time I found it very difficult to leave the house after that.'
Mr Roberts-Smith denied ever hitting Person 17 and said domestic violence was 'deplorable' and 'a disgusting act of of cowardice'.
'I have no tolerance for anyone who would ever raise their hand against a woman,' he told the court.
'I'm feeling good mate, looking forward to finally setting the record straight,' Mr Roberts-Smith told Daily Mail Australia ahead of the hearing
Mr McClintock said Nine was falsely alleging Mr Roberts-Smith had punched Person 17 in exactly the same place where she had been injured in the fall.
Mr Owens has told the court that the day after the Canberra incident Mr Roberts-Smith and Person 17 exchanged text messages about what had occurred.
She had written: 'I feel awful. I made a doctor's appointment for this afternoon after speaking to [her husband] and sent him a photo.'
Mr Roberts-Smith allegedly replied: 'Does he think I did it?'
Person 17: 'Yeah, he did to begin with and he didn't believe I had fallen down stairs. I just told him what we talked about.'
She had also said: 'I've got some other bruises including a massive one on my thigh on the same side of my body which will hopefully make the falling story more believable.'
Mr Roberts-Smith allegedly replied: 'OK well hopefully he believes you.'
He told the court he had asked if Person 17's husband thought he had hit her because she was getting around with a large bruise on her head.
Former governor-general Dame Quentin Bryce pinned Mr Roberts-Smith's Victoria Cross to his chest (pictured) and was expected to give a character reference at trial, however reports have claimed she has withdrawn
Mr McClintock said within a week of Person 17 sustaining the injuries she went to the Roberts-Smith matrimonial home and told his then wife she had been having an affair with her husband.
Ms Roberts and her mother asked about Person 17's facial injuries and she said she had fallen down stairs, Mr McClintock told the court.
Person 17 said the same thing to a doctor and a complaint she later made to police was eventually withdrawn.
The court has already heard Mr Roberts-Smith lost $475,000 in earnings from public speaking engagements after he was accused of war crimes and domestic violence.
Mr Roberts-Smith is suing Nine-owned newspapers The Sydney Morning Herald and The Age, plus The Canberra Times over allegations he committed battlefield crimes including murder.
Ms Roberts is set to give evidence against her now former husband for Nine.
Among Mr Roberts-Smith's claims is that the Nine Entertainment publications wrongly made out that he 'broke the moral and legal rules of military engagement and is therefore a criminal.' Mr Roberts-Smith is pictured in Afghanistan