To celebrate Smith's self-proclaimed status as a "Harmonizer," the two broke out into a karaoke cover of their hit single "Work From Home," but it only lasted a few moments before Corden said he just wasn't feeling it.
Pulling over to the side of the road, Corden pulled out his cellphone and called an unknown number. Speaking to the person on the other end of the line, Corden explained that he and Smith were singing "Work From Home," but he felt "it could be elevated somehow."
Smith, who was confused when Corden pulled over, suddenly shot Corden a very dubious look, and, as the girls of Fifth Harmony ran up and hopped into the backseat, the legitimately surprised pop star completely lost his cool.
"Oh I'm dead! No! Oh my god!" Smith screamed as he first tried to hide in his seat and then excitedly gave out hugs. "I'm shaking. I'm actually shaking. Oh my god, this is my dream!"