Rolf Harris has admitted he may have sexually admired his daughter's friend when she was 13 and also acknowledged he disguised "the dark side" of his character for decades.
Harris was grilled by prosecutor Sasha Wass QC on Wednesday about his "ridiculous" claim he'd had a 10-year consensual affair with Bindi's friend when she was an adult.
The main complainant in the sex abuse case alleges Harris first indecently assaulted her when she joined the Harris family on an overseas holiday in 1978.
"This was child abuse, grooming, you effectively psychologically dominated this girl into womanhood," Ms Wass said at Southwark Crown Court.
The prosecutor suggested that when Harris said Bindi's friend looked great in a bikini on the holiday he was actually saying she had a great body because the bathing suit was just a few pieces of small fabric.
"I suppose so," Harris replied in a soft voice.
Asked whether that meant, in hindsight, he admired his daughter's friend sexually at the age of 13, the entertainer said: "It's possible, yes."
Ms Wass on Wednesday argued that admission suggested everything the alleged victim had said was therefore "realistic".
"No," Harris replied. "Because it didn't happen."
Harris played up for the jury when the defence opened but Ms Wass said while he was a polished performer the trial wasn't a talent show.
Rather it was about whether the Australian had a "darker side" beneath his friendly and loveable exterior.
Ms Wass said the fact he'd successfully kept secret two affairs - he revealed the second, with his female driver, on Tuesday - meant he was good at disguising his dark side.
"Yes," Harris admitted.
Ms Wass told the defendant he'd tailored his entire case around a letter he wrote to the father of Bindi's friend in 1997 apologising for his behaviour.
"You've given away rather too much in this letter," the prosecutor said, adding it didn't make sense if the pair had had a consensual relationship.
The barrister made much of Harris's admission that: "When I see the misery I have caused (the alleged victim) I am sickened by myself."
"What had you done to make her miserable?" Ms Wass asked repeatedly.
Towards the end of the gruelling cross-examination, Ms Wass asked Harris if he knew what could have transformed a shy little girl from a good home into the recovering alcoholic the court heard give evidence a fortnight ago.
"She was emotionally dead," Ms Wass said.
"She was a damaged person. She was able to speak in the most blunt terms about things that must have been quite horrible."
Harris said perhaps the alleged victim felt like a "scorned woman" after the affair ended and he started a fling with another woman.
But Ms Wass was incredulous. She pointed out that even on his account there'd been no passion, no love, just "no frills" sex.
Harris had earlier admitted the pair "hardly ever spoke" which prompted Ms Wass to ask: "Did you treat her as a human being at all?"
"There wasn't a friendship," she said. "She was just there for sex."
Harris agreed, stating: "It would seem so."
The artist and singer on Wednesday was also forced to admit he lied in his first defence statement when he claimed he'd had just two sexual encounters with his daughter's friend.
In fact he'd had eight over 10 years.
The TV star justified his behaviour by saying he was embarrassed when he gave the statement because there were two "attractive young ladies" present in his solicitor's office.
He added that he thought he was being asked about penetrative sex and most of the encounters involved oral sex.
The 84-year-old is charged with indecently assaulting four girls in Britain between 1968 and 1986.
The celebrity stated: "They are all making it up."
