The Oscar winner made the confession Friday on the red carpet at the Toronto International Film Festival, where she locked lips with her Ruth & Alex costar.
"Look at him!" she told ET Canada as she grabbed Freeman's cheeks and pulled him in for a kiss.
Courtesy ET Canada
"Why don't you just admit it, just admit that you'd spend 40 years with me in your real life," Keaton, 68, teased Freeman, 77.
"I would! In a heartbeat," he replied.
"He refuses to give me a chance," Keaton lamented, to which her costar responded, "We've been waiting for each other all our lives."