Colleague sleeping with consenting adult students

have a male colleague who uses his status as a university professor to flatter and pursue multiple adult female students. After getting what he wants, he drops them abruptly and, in some cases, humiliates them for being “gullible.” The university is aware of the situation but says it will not intervene because these are consensual relationships between adults. There is typically a 15–25 year age gap between the students and the professor.

I find it very difficult to witness this. I consider it predatory behavior. Many of these female students have left the university afterward, feeling ashamed. Beyond my personal opinion, I believe this could be considered a systemic barrier to female students pursuing and completing their education.

I don’t know what to do.