Hostile Work Environment:

So What Is Unwelcome Or Offensive?

In this case, unwelcome simply means the employee didn't invite the conduct or want it to happen. Offensive means that a reasonable person, meaning someone of a similar background who's not too sensitive or too insensitive, would find the conduct rude or distasteful.

But keep in mind that an isolated incident of inappropriate behavior, even if it is unwelcome and tied to a protected characteristic, isn't necessarily harassment under the law.