You shouldn't base your treatment of people on their sex.
Bob runs an all male department but today a female employee has been added to his staff.
Bob wants to incorporate the new employee into the department.
Bob has a meeting to identify her strengths and weaknesses and then assigns her tasks accordingly.
Bob asks the female employee to take over the responsibility of making coffee and ordering meals for the department.
Bob utilizes his new employee to the fullest extent.
Bob gets hit with a sexual discrimination complaint.