"They said I groomed someone!"
An assistant coach takes a special interest in a young athlete, dedicates extra time, and is soon accused of inappropriately touching a minor. Whether the minor flirted, enjoyed advances, or helped create compromising situations will always be irrelevant.
Just down the street, an empathic and caring therapist feels great heartache for a highly abused client. Sessions always feel cut short and an invitation is extended to meet less formally for a longer uninterrupted conversation. Both enjoy it and find it therapeutic, and a dating relationship soon develops.
At a nearby university, a professor takes a special interest in an awkward graduate student whose gifts and worth have gone unappreciated, and a special bond develops. Fill in the rest.
At a local church, a beloved and effective pastor working non-stop makes time after hours for one more advisee -- whose husband has forgotten her value.
At the local hospital, a nurse loses his career after accepting a social invitation from a patient who is back on their feet.
Back at the nearby high school, a teacher grows very fond of a particular student who shows appreciation for the important life lessons being added to calculus.
These stories have several things in common, and none lead to a good place for either person. Even when no abuse or exploitation is intended, like with that "poor abused client who is finally able to experience being treated with dignity and honor!" such relationships can be predicted to fail and cause harm and strife to both parties. For example, they will never undo the leader/follower basis of the relationship, and the secrecy is a large burden to maintain especially among family, friends, etc. Even regardless of ethics and licensing Boards, the likelihood of being a sustainable weight-bearing and stress-enduring relationship is very very small. Each usually only knows what the other presented about themselves, rather than what they are really like over time, and time is not on their side as they correct their assumptions, hopes, and idealizations unravel. Normal relationships are already hard enough to develop and navigate without the added pressures of secrecy or obstacles to "turning back."
Of course, unethical and regrettable things do not occur when everyone is feeling perfectly rational, well-rested, content, and funtioning at 100%. But depending on the number of pressures and problems involved, the intensity of temptation, realities of fatigue and frustrations, and then a sudden occurrence of opportunity or encouragement, anyone can have a moment of weakness. And by analogy to alcohol and driving, it's quite unlikely that an impaired person recognizes their impairment when it counts. It's important to remove all naivete about how much more painful an already struggling life can suddenly become, and to recognize what is actually happening on a rather widespread level in society.