Sexual relationship is meant to be consensual. This means it is something that is expected to take place between two adults who have an agreement to do so. What this means is that when either of the partners is forced, it becomes a case of rape, and that is criminal. It becomes more complicated when the victim is a minor.
https://www.sunnewsonline.com/raped-and-abused/
https://www.sunnewsonline.com/raped-and-abused/