De Niro is expected to resume testifying on Tuesday.
He is countersuing Robinson, alleging that she abused a company charge card for personal expenses and vacations.
Todays trial pulls together both De Niros initial suit andRobinsons countersuit.
Robert De Niro arrives at federal court on October 30David Dee Delgado/Getty Images
Each blames the other for a troubled working relationship that ended with Robinson resigning that spring.
Robinson was 25 years old when she signed on in 2008 to be De Niros executive assistant.
De Niro also stood idly by while his friend slapped Ms. Robinson on her buttocks.
He would joke with Ms. Robinson about his Viagra prescription, according to the lawsuit.
De Niro smirked to Ms. Robinson about his young paramour, who was around Ms. Robinsons age.
De Niro directed Ms. Robinson to imagine him on the toilet.
He told Ms. Robinson that doing manual labor would make a man out of you.
De Niro suggested that Ms. Robinson could get pregnant using sperm from her (married) male co-worker.
Dominic Patten contributed to this report.
