SAN FRANCISCO (KRON) -- Accused Bob Lee murderer Nima Momeni testified on Wednesday about the night the tech mogul was fatally stabbed. Momeni said Lee exploded with anger over a joke prior to the stabbing. Momeni claims he told Lee that the tech mogul should be spending time with his family, instead of partying at strip clubs. Momeni testified, “I made a bad joke. I said if it was my last night in town, I'd go hang out with my family instead of f**king around in strip clubs. It set him off. He just blew up in front of me. He went from zero to one hundred. He was very angry.” What is Bluesky? Emerging social platform tops 15M users in wake of election Momeni testified that his sister Khazar Momeni asked him and Lee to leave her apartment in Millenium Tower at 2 a.m. on April 4, 2023, because she was mad and wanted to sleep.  Nima Momeni (Sketch: Vicki Behringer) Jurors watched surveillance video showing Lee and Momeni get into an elevator together as they left the tower. Lee had a beer in his hand, because he wanted a drink "to-go," Momeni said.  Defense attorney Saam Zangeneh asked Momeni what Lee and Momeni had planned to do next.  "We were just talking about stuff to do," Momeni replied. "She was pretty mad, so we just left quickly." "When you guys were leaving, were you arguing?" asked Zangeneh.  "No. It's past 2, so bars are past last call," said Momeni. "No drinks at the strip club."  Momeni testified that he just started driving and as the they drove around San Francisco in Momeni's BMW, Lee spilled his beer in his lap and asked Momeni to pull over. As Momeni pulled a towel out from under his seats, Lee spotted a nitrous whippet next to the towel and huffed it, he testified.  Momeni said, "He found my sister's nitrous. She left it before leaving the car to go see Dino (Elyassnia, Khazar's husband), because Dino doesn't like that. She didn't want to take that back upstairs. (Lee consumed) a bunch of the canisters."  "After he did that, what was his reaction?" the attorney asked?  "He was being silly, chatty, making weird noises," said Momeni. "He left the car, I thought he was going to puke so I followed him out."  Momeni testified that Lee wanted to keep the party going by retrieving more cocaine from his hotel room. Momeni told jurors that he just wanted to end the night, especially after Lee spilled his drink.  Nima Momeni in court (Sketch: Vicki Behringer) "Did something change the mood? What did you say that changed the mood?" the attorney asked. Momeni said, "I made a bad joke. I said if it was my last night in town, I'd go hang out with my family instead of f**king around in strip clubs. It set him off. He just blew up in front of me. He went from zero to one hundred. He was very angry.” "Did you tell him it was a bad joke?" the attorney asked. "Yes, I did," Momeni replied. "Everything I said just made it worse. He's yelling, cursing at me, circling around me, getting in my face.”  In the courtroom gallery, Bob Lee's brother shook his head in disgust in reaction to the testimony. Lee's father was also in attendance. The defense attorney replayed a grainy Nest surveillance camera's video, the only video that exists of the actual stabbing. Zangeneh told Momeni to stand up and tell the jury what's happening in the video. "I'm facing Bob. He's cussing at me, he's yelling at me, talking about parenting,” Momeni said. "What was your first reaction when you saw the knife?" the attorney asked.  Momeni said, "I was afraid for my life. I just wanted to control his hand. I grabbed his hands, I tried to control it, I was grabbing it and pushing him backward. He took a swing."  Momeni and his defense attorney acted out the altercation, allegedly re-creating what happened for the jury.  Nima Momeni and his attorney (Sketch: Vicki Behringer)  Zangeneh pretended to hold and knife and swing it toward Momeni. Momeni grabbed his defense attorney's arm and re-directed it back toward the attorney's chest.  Momeni testified that when Lee walked away after the altercation, he had no idea that Lee was badly injured. "He just turned around and started walking away," he testified.  Momeni said that he didn't want Lee to get the knife again, so when he saw it on the ground, he grabbed it and threw it over a fence.  According to previous trial testimony, Lee was stabbed three times, including a fatal blow through his heart. He left behind a heavy blood trail between where Lee was stabbed and where he collapsed unconscious in the street.  The accused killer told jurors that he had no idea Lee was killed until someone told him on April 5, 2023.  Momeni said he was "in shock" as he drove from the crime scene to his home in Emeryville. "I was in shock. I was just attacked," he said, "this was not a normal situation."  The defense asked Momeni if he called anyone after altercation.  "I called my sister. I told her 'Bob went crazy, don't let Bob back in. He just went crazy on me and attacked me,'" Momeni answered.  "Did you know Mr. Lee was fatally injured?" the attorney asked. "Absolutely not," Momeni said. "He seemed normal as he walked away."  Nima Momeni (Sketch: Vicki Behringer) Momeni seemed stoic on the stand Wednesday. He appeared at times to be mumbling but seemed focused. At one point during his testimony, he broke down in tears in front of jurors.