'Psychotic': Robert De Niro's GF Tiffany Chen Testified That Ex-Assistant Had 'Imaginary Intimacy' With Actor

Robert De Niro's girlfriend, Tiffany Chen, took the witness stand and testified over her disapproval of his former assistant on Thursday, RadarOnline.com can confirm.

Chen told the Killers of the Flower Moon star in a series of emails shown to the jury that she felt Graham Chase Robinson was having "imaginary intimacy" with the actor, describing his ex-staffer as a "mean, insecure, territorial girl" who "thinks she's your wife."

Chen likened her boyfriend's ex-staffer to the lead star from the 1992 psychological thriller Single White Female.

In court, Chen explained what she meant by this reference, a woman who is "obsessive, crazy, and dangerous."

Another exchange from Chen to De Niro stated, "I'm not going to be happy until you tell me she's looking for a replacement. Keeping her around is just a slap in my face."

He denied being given an ultimatum by Chen. "No one tells me what to do in my office. Period!"

One of Robinson's attorneys, Brent Hannafan, also denied that his client was "in love" with the 80-year-old Goodfellas actor.

As we previously reported, De Niro filed a $6 million lawsuit for breach of loyalty and fiduciary duty against his ex-assistant who worked for him between 2008 and 2019, claiming she binge-watched Netflix while on the clock, used his company's credit card for personal expenses, and transferred millions of airline miles for her personal use without being granted permission.

Robinson, who used to work for De Niro at Canal Productions, fired back by accusing the film star of gender discrimination and retaliation in a $12 million countersuit four years ago.

Hannafan claimed she "had to be on call all the time," but he shut down those claims. "You're making it out like I controlled her."

"I believe in the honor system," De Niro said. "I only value work if it is done right, or else it reflects poorly on me."

She also alleged that he once urinated while on the phone with her, made her scratch his back, and had called her a b---- to her face. "I may have been in the bathroom," De Niro said. "I didn't realize I was talking. Come on! You got us all here today for this?"

De Niro said he was "never abusive."

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At one point during his own testimony, De Niro looked at his former staffer and said, "Shame on you, Chase Robinson."