When former President Bill Clinton appeared on "The Late Show with David Letterman," he was sure not to let anything slip about his wife Hillary's potential 2016 plans.
Letterman -- who offered to share office space with "anybody you know who's running for president" -- told Clinton to blink twice "if [Hillary] is running to your knowledge."
“I blinked once!” Clinton responded.
All joking aside, Clinton said that if he did know his wife's plans, he wouldn't tell Letterman.
"I honestly don’t know, Chelsea doesn’t know, and Hillary doesn’t know," Clinton said.