In the Harvey Weinstein situation, an actor or crew member working on a film that he produced, or any person working at The Weinstein Co., would be an employee under the law.

The old trope of the casting couch has never really died. In recent days, it has been renewed and recast by the news about Harvey Weinstein’s alleged sexual harassment and sexual assault of a growing list of women in hotel rooms and offices across the country. It has become apparent there is no clear understanding of where the line is between harassment and a consensual relationship when something happens between a boss and employee.

The laws against sexual harassment — Title VII in federal law, the Fair Employment and Housing Act in California and the New York Human Rights Law, among others — apply to the employment context. In the Weinstein situation, an actor or crewmember working on a film that he produced, or any person working at The Weinstein Co., would be an employee under the law. But the law also applies to applicants, and women who agreed to meet with him because they hoped that he would cast them for a film likely would be covered by the laws against harassment.

The laws against sexual harassment do not prohibit all sexual conduct in the workplace. If an affair or sexual relationship truly is consensual, it can be legal. But the fact that sexual conduct was voluntary, in that the victim was not forced against her will to participate in the sexual activity, does not make the conduct consensual and legal. The central question of any sexual harassment claim is whether the sexual advances were unwelcome.

When a supervisor dates a subordinate, it is difficult to show that the advances were welcome and the relationship was consensual because of the differential in power. When people have differing levels of power, a sexual advance may feel compulsory. When a supervisor, for example, asks a subordinate employee for sexual favors, that employee could very well believe that their continued employment depends on whether they agree to the sex. The coercive nature of supervisor/employee relationships brings up a serious question of whether sexual relationships between the two parties are truly consensual.

Courts have recognized two kinds of sexual harassment. The first is “quid quo pro” — or “this for that” — harassment, where the person in the position of power promises a job benefit — a role, a job promotion, a compensation increase — if the victim submits to his sexual advances. Quid pro quo harassment also exists where the person in the position of power makes a threat of termination, blacklisting or job loss if the victim refuses the sexual advances. This is the behavior that some women allege that Weinstein engaged in. It often is easy to identify as inappropriate and unlawful.

The second kind of harassment is “hostile work environment” harassment, in which sexual conduct is so severe or pervasive that it creates an abusive working environment. This behavior sometimes is more difficult to identify as unlawful. The Supreme Court recognized this kind of harassment for the first time in 1986, in a case called Meritor Savings Bank v. Vinson. In that case, Mechelle Vinson claimed that Sidney Taylor, the vice president of the bank, coerced her to have sexual relations with him and made demands for sexual favors while at work. Vinson said that she had sexual intercourse with Taylor 40 or 50 times.

The court in Vinson decided that Taylor’s conduct amounted to hostile environment harassment. Even though Vinson and Taylor had sex multiple times and the sex was voluntary, in the sense that Taylor did not force Vinson to have sex with him, the advances and thus the sex were not welcome. The important lesson for people evaluating a situation they are in or know about is that, even if a subordinate employee has sex with her boss one time or many times, the relationship may nonetheless amount to unlawful harassment. The question is whether the advances were welcome and whether the victim by her conduct indicated that the alleged sexual advances were unwelcome, not whether her actual participation in sexual intercourse was voluntary.

Sexual harassment that creates a hostile or offensive environment is a barrier to gender equality in the workplace. The requirement that a person run a gauntlet of sexual abuse in return for the privilege of being allowed to work is demeaning and troubling. If the unwelcome conduct is sufficiently severe or pervasive to alter the conditions of the victim’s employment and create an abusive working environment, it is unlawful.

If the Harvey Weinstein situation teaches us anything, perhaps it will teach us that sexual conduct and sexual advances, if they are not clearly welcome, are inappropriate and probably illegal. It is up to all of us to make sure that this conduct stops and to change the culture that allowed it to fester.

Ann Fromholz is a Pasadena-based employment attorney who specializes in workplace investigations into sexual misconduct and harassment, discrimination and retaliation.