I’ve heard several variations on this, including:
“Thank you, I’ll be here all week.”
“Good night, thank you, be sure to tip your waitresses.”
“Thank you, good night, drive safely.”
Obviously, these are all sign-offs that standup comedians have done for years. But I’ve invariably heard them after someone has just told a joke that utterly bombed. A friend may tell a joke he thinks will get a huge laugh, and when the reaction is deafening silence, he’ll try to escape with a smile and a “Thank you, I’ll be here all week.”
It’s become shorthand for, “I see now that joke was a stinker- sorry!”
For decades, David Letterman has been saying “Good night, drive safely,” after a joke goes over badly. He may have been the one to perpetuate the idea that an old Catskills comedian’s sign off was a safe way to apologize/duck responsibility for a bad joke.