The ex-MP entered the witness box on Wednesday in a Sydney court where Jones is fighting 22 charges of indecent assault and sexual touching without consent in relation to six men.
Eight charges relate to the former radio staffer, who claims he was kissed without consent in lifts and groped by the former top-rating breakfast radio host while driving and at an event.
Years later, the staffer came face to face with Jones and looked uncomfortable, the former politician told Downing Centre Local Court.
"I could see (he) was feeling quite uncomfortable sitting next to me," he said.
"(He) was sunken and diminished".
The younger man was normally outgoing and engaged but he avoided eye contact and remained silent during the conversation, according to the former Liberal MP.
"I could tell he was anxious and uncomfortable," he told the court.
He said the man's discomfort deterred him from asking questions about the encounter afterwards.
But the former politician agreed under cross-examination he couldn't know how the man was feeling and hadn't expected him to contribute to the conversation.
The alleged victim previously testified the encounter with Jones, a former Wallabies rugby coach turned conservative commentator, had left him anxious and uncomfortable.
When pressed on why he had subsequently messaged Jones to say it had been lovely to see him, the man said he had sent an insincere text to placate the longtime shock jock.
During his evidence, the complainant said he partially disclosed the indecent assaults to friends, family, and colleagues over the years.
His friend recalled being shocked when the staffer told him Jones had squeezed his crotch while he was driving.
"I said 'what the f***?' and he said to me 'that's just Alan, that's his behaviour'," he said.
The staffer told his friend Jones was a "very powerful person", the court was told.
He had used the words "go the grope" when describing how Jones would put a hand on his leg, a former colleague testified.
She said the man recounted brushing the record-breaking radio host's hand off his leg and saying no, leading Jones to laugh it off.
She said the complaint had been made in a jovial manner and they didn't discuss it again.
Jones, 85, has pleaded not guilty to the charges related to six men, alleged to have occurred between 2003 and 2020 - the year he retired from radio.
The staffer's father-in-law said he was surprised to learn the man was considering taking action against Jones, including considering civil alternatives.
"(The radio staffer) told me he was absolutely sure he was doing the right thing," his father-in-law wrote in a statement to the court.
He said the complainant had told him Jones pushed him up against a wall and kissed him.
His son-in-law also described the breakfast host inviting him to his apartment, where he was sitting in only a dressing robe so "his undercarriage was hanging out".
Jones, whose 35-year career spanned TV and radio, has dismissed the allegations by the six complainants as false and motivated by matters including rivalry, treachery and hatred.
The hearing, expected to run four months, continues.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
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