The 77-year-old Oscar winner was spilling secrets on "The Ellen DeGeneres Show," which airs today, while playing a game of "never have I ever" with host Ellen DeGeneres.
"Never have I ever joined the mile high club," DeGeneres said, reading from a card.
Fonda held up a paddle which read, "I have," before explaining "I was 50 years old. It was my fourth date with Ted Turner. He has his own plane, and we get on the plane, and he said, 'Are you a member of the mile high club?' I didn't know what he was talking about."
The actress soon learned.
"I joined!" she exclaimed. "Suddenly the seats became a bed."
Fonda also revealed that she had made out with someone half her age.
"Just make out, right?" she clarified.
"Whatever you want to share with us, but yes" DeGeneres quipped.
"That's all," Fonda said.
When DeGeneres read, "Never have I ever hooked up in the bathroom at a party," Fonda hesitated.
"Dou have to tell the truth?" she asked with a laugh.
She then revealed that she had but still wanted some clarification.
"What do you think 'hook up' means?" Fonda asked.
DeGeneres replied, "Probably a little more than making out... But it could be all kinds of things."
Fonda once again held up her paddle, which read, "I have."
"I stick with that," she said.
The actress was also asked if she had ever been drunk before noon or stolen something. Watch the video below to find out what she said.