of course… not

A phrase that often excites someone and then disappoints them a second later, however sometimes this phrase can make someone angry but relieve them later.

A: Can you give me 15K bucks?
B: Of course…
A: *trembling with excitement*
B: not…
A: *excitement fades away*

A: Would you be happy if I ran away?
B: Of course… not.
A: You got me there for a second!