Female scientists encounter many obstacles, and we’re getting better at talking about them. Except for one. In the wake of the sex scandals coming to light in other industries, I think it’s time to address the elephant in the room: the supervisor who is “hands on”… and not in a good way.

This damages everyone, not just the participants. A young scientist whose supervisor has a reputation for dalliances may find that other people assume she must have slept with her boss. This throws into doubt the integrity of any recommendation the supervisor makes of her. People may assume that she has come to her current position unfairly, or that she has been given more authorial credit on joint publications than she really deserved.

Being associated with a seducer-supervisor also leaves young scientists open to harassment. At the bar at a conference, I was asked by a professor twenty years my senior whether I had ever slept with my supervisor. Taken by surprise, I answered that I hadn’t and steered the conversation back to science. It was only later that I started to wonder why he would ask me that. Was he just seeking a point of information? Or was he trying to work out how an advance from him might be received?

And if these things have happened to me just because I happen to have worked with a scientist who has a reputation, what happens to those young scientists who actually sleep with their boss?

When I express these opinions in the tea room, they’re surprisingly controversial. “Why shouldn’t two consenting adults sleep together?” people ask. But when one person holds so much power over the other, can we really be sure that consent is freely given? UK law recognises that the issue of consent between teachers and students is more complex than in other relationships, which is why the age of consent is 18, not 16, in such cases. Of course, PhD students usually are over 18, so sleeping with your PhD student is unlikely to be a criminal matter, but that doesn’t mean that doing so is professional. Or right.

“But what about true love?” they say. And I’ll admit that I know a handful of marriages that started off as supervisor/student relationships, although I suspect that only a very small fraction of such relationships end at the altar. I’ll also admit that, even when there’s a happy ending, I do think less of the senior participant. But there are solutions here. The least disruptive is simply to wait to pursue the relationship until after the student has graduated. And if waiting really isn’t an option, it’s possible to transfer supervisors, which students regularly do for a variety of reasons.

I find it telling, though, that the “true love” defence is most often put to me by students, rather than supervisors. Could it be that the supervisors know something the students don’t?