Francesco Zumbo manipulated his young employees, pressuring them into "kisses and cuddles", touching them inappropriately and exposing himself to one victim.
The 56-year-old was convicted at Sydney's Downing Centre Local Court on Friday for crimes that occurred at various locations across the city from 2014 to 2018.
Zumbo sat alone on one side of the courtroom while the victims and their supporters sat in a group on the other side as Magistrate Gareth Christofi delivered his judgment.
Charged with recruiting staff for the then-Liberal MP's office, Zumbo met the four young women who were all around 30 years younger than him through either his work at university or high school events.
Multiple complainants say the former aide would greet them with hugs and kisses in the office, conduct which escalated to him groping their breasts or touching their backsides.
Zumbo claimed it was part of his Italian heritage to greet people in this way.
One woman said her boss exposed his penis to her while they were on a park bench, while another said he touched her vagina while they were pulled over in his car by the roadside.
Mr Christofi found there was clear evidence Zumbo was sexually attracted to his staff members, who were in their late teens or early 20s at the time.
Covertly recorded conversations showed the officer manager repeatedly saying he was in love with, attracted to and wanted to become intimate with the women, the magistrate said.
These discussions were one-sided and Zumbo would not take no for an answer, questioning his staffers' loyalty and pulling them into lengthy rants if they rejected his attempts at intimacy.
"An appropriate professional working relationship this was not," Mr Christofi said of his conduct with one complainant.
"Given the grossly lopsided power dynamic, the relationship was abusive and manipulative."
Zumbo will be sentenced on March 26 for seven offences, including six counts of aggravated indecent assault and one count of indecent assault.
The magistrate acquitted him of two further charges of aggravated sexual touching relating to a fifth complainant.
He said he could not be satisfied beyond a reasonable doubt that Zumbo's touching of a teenager's thigh and rubbing of her shoulder was of a sexual nature.
Zumbo remains out on bail after Mr Christofi dismissed a detention application by the Crown.
He found it was only likely and not inevitable that the former aide would face full-time imprisonment for his crimes.
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