Mr. Thompson, You Found the Wrong Girl - Episode 18

The female protagonist, Katie, accidentally stumbles into James's room one drunken night, and they spend the night together, both unaware of each other's true identity. The next morning, Katie realizes that she has "accidentally" had a one-night stand with the company's CEO, James. She tries to downplay the awkward experience, but it leads to more and more intersections in her life with James.