The Social Network actor stars alongside The Big Bang Theory's Kunal Nayyar in the dark comedy in London, following a run on Broadway, and they both admit they get nervous before every performance because anything can happen.

As an example, Jesse revealed to U.K. show This Morning that he vomited on stage just last week (ends26Jun16) while he was having an argument with Kunal, and the audience had no idea they were witnessing an unscripted moment.

"Last week, Kunal and I are screaming at each other on stage and I threw up," Jesse said, before Kunal added, "You choked. You were trying to swallow air to try and make your next point and bile came out."

Kunal has also accidentally punched Jesse in the face during the show, and had to blow his nose onstage because his allergies were getting the better of him. He smiled, "I literally had snot leaking out my nose... it was an emergency."

Jesse reluctantly signed on to star in his own play because he gets "terrible near-debilitating stage fright" but admits it would be worse for him to not do it.

The duo are still as nervous following around 200 performances as they were on day one because they just don't know what to expect.

"For some reason, I think, because we still have to do the entire play, even in the last performance... so I'm still panicked about the whole thing," Jesse explained. "I think I can come up with anything to worry about."

"We all get it, by the way," Kunal interjected. "You're on stage for two hours and 15 minutes and anything can happen at any moment. There is this feeling you're standing on the edge of a cliff... you're teetering on that line the entire show."

The Spoils runs at the Trafalgar Studios until 13 August (16), although Kunal will not be performing from the end of July (16).