What term refers to a behavior that is excessively forward or beyond what is considered proper?

The term that describes behavior that is excessively forward or beyond what is considered proper is "presumptuous." This word conveys a sense of overstepping boundaries or taking liberties that one does not have the right to take. For example, a presumptuous person might make assumptions about someone else's thoughts or feelings without having any justification for doing so, appearing intrusive or disrespectful in social situations.

In contrast, "pretentious" refers to an attempt to impress by affecting greater importance or merit than is actually possessed, often being related to claims of superiority or artificiality. "Pretext" refers to a reason given in justification of a course of action that is not the real reason, which does not apply to social behavior. "Profligate" describes someone who is recklessly extravagant or wasteful in the use of resources, which is also unrelated to the concept of being forward in a social context. Thus, "presumptuous" is clearly the most fitting term for behavior that exceeds normal social propriety.