Define Yank Your Chain Meaning

Tell someone you've been invited to the White House for dinner with the prez. Then you say, "I'm just trying to yank your chain."

John: You look so fat in that dress go change!
Jamie: but babe! *frowns and crys*
John: I'm just yanking your chain
Jamie: oh, whats that mean?
John: Im just joking!

Ryan: Hello

and everyone else ignors....

just yanking your chain