Scarlett Johansson says the robot sex scene in Her just about caused Joaquin Phoenix to short-circuit.

In Spike Jonze’s 2013 sci-fi romance, Scarlett plays Samantha, an Alexa-like virtual assistant.

Although Scarlett doesn’t actually appear on camera in the movie, her voice is omnipresent throughout, while Joaquin portrays Theodore, who eventually falls in love with the artificially intelligent assistant.

The two characters share an intimate scene in which Scarlett makes sex and orgasm noises.

She explained to Dax Shepard and Monica Padman on their Armchair Expert podcast this week that the offbeat sex scene was pretty awkward to put together.

The Black Widow star explained that Joaquin had already filmed his end of the scene, but because the film only features Scarlett’s voice, he needed to join her in a recording studio to work with her on her part.

“Joaquin comes in, we try to get through one take, and he was, like, losing it,” Scarlett recalled.

“He was like, angry … He had already done [the scene], he had done it in person, and now he was with me, in this weird theatre, I’m in this box and [Joaquin] is staring at me, the lights are low, and like, Spike is there. It was so bizarre.”

“Joaquin was so upset about it, he left the studio,” she added. “He needed a break.”

Scarlett said that thinking back on the scene today gives her “panic” and that she totally understood where Joaquin was coming from.

“You don’t want to hear your voice, ever,” Scarlett said about 46 minutes in. “You definitely don’t want to hear what you sound like having an orgasm. You definitely don’t want to hear what you sound like having a fake orgasm — ew. It’s so gross.”