Step-by-step explanation:
First thing, CHEATING is like a sweet nectar that makes one's intelligence and thinking ability dull and hollow. so, it's not our loss if someone is cheating, according to me we should only warn that person to not cheat next time, or we just report the invigilator about the cheating activity generally, not targeting anyone personally.
I don't think it is the ethical responsibility of students to report a particular student for cheating because it may become the matter of clash between you and them, and it may waste your time for none.
Cheating is also a sign of disrespecting of what the teacher had taught so we should just complaint the teacher in general about the cheating activity, and if teacher is concerned enough, they take cares next time.