Harassment covers a wide range of behaviors of an offensive nature. It is commonly understood as behavior that demeans, humiliates or embarrasses a person, and it is characteristically identified by its unlikelihood in terms of social and moral reasonableness. In the legal sense, these are behaviors that appear to be disturbing, upsetting or threatening. They evolve from discriminatory grounds, and have an effect of nullifying a person's rights or impairing a person from benefiting from their rights. When these behaviors become repetitive, it is defined as bullying. The continuity or repetitiveness and the aspect of distressing, alarming or threatening may distinguish it from insult.
This is a general view of harassment, it can help to identify anyone having this type of behavior. Some may claim they are just joking but be careful and report that person to the proper authority. Any time one is acting like this more than once it is harassment. And if you want to do it yourself be good at it ...