It's probably  best you watch this episode  on YouTube.  To fully enjoy  it!  

When we first meet young lovers Luke (Alden Ehrenreich) and Emily (Phoebe Dynevor) in Fair Play, they seem perfect for each other, sneaking off during a wedding to have messy sex in the bathroom which culminates in a spontaneous proposal. But this brief moment of carefree intimacy between the couple—who are also coworkers at a high-powered hedge fund—soon gives way to jealousy and mind games once Emily is promoted over Luke.

What follows is a study in male fragility, as Luke's career begins to suffer while Emily thrives in her new role, and female rage, with Emily bristling under the manipulation and increasingly humiliating outbursts from her fiancé.

Spoilers follow.
The rising tension between the two explodes over into their workplace when a visibly drunk Luke, who has been AWOL for several days, barges into an important meeting and reveals their secret relationship to Emily's boss, accusing her of sexual misconduct. While enraged in that moment, Emily later learns that nobody at the firm cares, as long as she is discreet: for better or worse, she is protected by her senior position at the firm, a position usually occupied by men.