This man figured out what his female coworker knew all along about workplace sexism

A man named Martin Schneider, now a writer and editor at movie news site Front Row Central, learned a powerful lesson about sexism in the workplace when he stepped into former female colleague Nicole Hallberg's shoes for two weeks. 

In a series of now-viral tweets from Wednesday, Schneider recalled how, when the pair worked together at a "small employment service firm," their boss' foremost complaints had been that Hallberg took too long to work with her clients.

One day, Schneider accidentally attached Hallberg's signature to an email he'd sent out, and he quickly figured out what happened any time Hallberg sent an email to her clients. The answer? Blatant sexism.

As an experiment, Schneider and Hallberg swapped email signatures for two weeks. During that time, Schneider said Hallberg had the "most productive week of her career," while Schneider said he was "in hell." Schneider ultimately realized Hallberg took longer to sort out issues with clients because she spent the majority of her time fighting to earn their respect.

"I wasn't any better at my job than she was," he wrote in a tweet. "I just had this invisible advantage." 

When Schneider presented their boss with the results of his and Hallberg's email signature switch, however, the boss remained staunch in his views, denying the existence of workplace sexism. 

Hallberg explained why that might be in a Thursday post on Medium, where she recalled her experiences with her boss' own sexism.

In one conversation, Hallberg's boss told her Schneider was "kind of a girl" because he could be emotional sometimes. Another time, the boss told Hallberg he "took a chance" on hiring a woman because he didn't want to "change the atmosphere of the workplace."

"What did my boss have to gain by refusing to believe that sexism exists?" Hallberg wondered. "Even when the evidence is screaming at him, even when his employee who makes him an awful lot of money is telling him, even when the boy on staff is telling him?"

Hallberg said she never figured out the answer to that question. While most women's experiences with sexism don't include a happy ending, Hallberg's does: She eventually quit her job to become a freelance writer.

She wrote, "In an office of one, I can finally put my walls down."