Jane Fonda joined Mile High Club with ...

Yes, Jane Fonda admits, she is a member of the Mile High Club.

Fonda, 77, says it happened when she was 50 and on her fourth date with (now ex-hubby) Ted Turner.

"We were on his private plane," she explained. "And he said, 'Are you a member of the Mile High Club?' And I didn't know what he was talking about."

She added, "And then I joined."

The revelation is made on today's Ellen DeGeneres Show in a game of Never Have I Ever, in which Jane and Ellen hold up paddles answering questions. Among Fonda's other admissions: She hooked up in a bathroom at a party and she once shoplifted a half slip in Omaha.