The New York Times Magazine recently profiled the troubling, potentially criminal relationship between a former Stanford student, Ellie Clougherty, and entrepreneur Joe Lonsdale who was, among other things, Clougherty’s mentor for the undergraduate course Engineering 145: Technology Entrepreneurship.

As the story unfolds, it becomes increasingly disturbing. Lonsdale and Clougherty’s relationship evolves from that of a mentor and mentee into a romantic relationship and then, Clougherty alleges, into something much more disturbing—including sexual harassment and assault. Clougherty took the case to Stanford officials and Lonsdale was banned from the Stanford campus for ten years (though that ban seems theoretical at best, given that, according to Bazelon, “Lonsdale has been invited to campus for a private lunch which he attended with the university’s permission.”). Clougherty filed a civil suit in January and Lonsdale has responded, vigorously, and filed a countersuit, denying Clougherty’s accusations.

Clougherty graduated from Stanford in 2013 and is looking to build a career that involves brain research, tech and social activism.

It’s a murky situation—but a mentoring relationship went horribly wrong. Clearly both professional and personal boundaries were crossed inappropriately—and a young woman who was supposed to be mentored and encouraged professionally was, instead, embroiled in what was, at best, an unhealthy relationship with someone who possessed undue influence.

There is ample evidence that mentoring for college students can have a significant impact on how prepared recent graduates feel as they enter the workplace. A 2014 Gallup study of 30,000 college students found that mentoring opportunities were remarkably important to long term career success and satisfaction. Brandon Busteed, the executive director of Gallup Education noted how the study revealed that, “the three most potent elements linked to long-term success for college grads relate to emotional support: feeling that they had a professor who made them excited about learning, that the professors at their alma mater cared about them as a person, and that they had a mentor who encouraged them to pursue their goals and dreams.”

Lonsdale never treated Clougherty as someone who had goals and dreams. Instead, Lonsdale, by engaging in a personal relationship with his young mentee, treated her as a romantic conquest. He ignored his professional responsibility for personal gain. Lonsdale insists that, “Ellie is a forceful person,” as if, somehow, that negates the inherent power imbalance not only in a mentor/mentee relationship, but also between a 21-year old college student and a hugely successful 29-year old entrepreneur.

It should go without saying, but mentors cannot treat the mentor/mentee relationship as a garden of earthly delights. They have one primary responsibility in such a relationship—to provide support and guidance for young men and women. Mentees are not potential romantic interests or sexual conquests. They are not potential acolytes or personal assistants. The mentor/mentee relationship is a professional one and should be treated as such. If there is a temptation to cross lines, resist. There is a responsibility attached to being a mentor. Mentors must live up to that responsibility. It really is that simple.

Alumni are a natural source of mentoring for colleges and universities. These alumni and their success stories are living proof that the education at any given college or university works, and that the current students are making a wise, invaluable investment in their future. Joe Lonsdale is one of countless alumni who have been tapped by their alma maters to work with promising undergraduates. Unfortunately, though, many universities seem to think that getting mentors on campus is all they need to do. There is, all too often, little oversight and few systems in place to help students when these relationships become troubled.

Universities and colleges can’t merely provide mentoring opportunities for their students. They need to monitor those relationships to ensure they are functioning productively and mutually for both the mentor and the mentee. There needs to be a system of checks and balances, if you will. Had the professor of the course who originally assigned Lonsdale to mentor Ellie Clougherty engaged in even the most basic of oversight, a great deal of suffering might have been averted. We cannot undo what has been done but universities and colleges can work to ensure that such a problematic mentoring relationship never happens again.

Roxane Gay is an English professor at Purdue University and a New York Times best-selling author. She’s written Ayiti, An Untamed State, Bad Feminist, and the forthcomingHunger. She is also editor of The Butter. Roxane’s column for Fortune, “Beyond the Workplace,” will delve into why corporate America should care about the social issues happening outside of the office. Follow her at @rgay.