A slightly embarrassed coda to a statement, used by people over a certain age when they realize that:
  1. They have just used a slang term commonly employed by people half their age, or
  2. They have just used a slang term that is now hopelessly out of date, and
  3. They probably sounded pretty square* when they did it.

Indicates a sudden consciousness that one is not a kid anymore and no longer has any business referring to something as "dope".**

* As the kids say.

** As the kids say.