On an episode the U.K.'s Graham Norton Show airing next week, Rudd is asked about his onscreen smooches alongside Mirren and fellow guest Leslie Mann.
"The most kisses I've had in a movie was with your hero Jack Nicholson," Rudd says to Mirren. "Many, Many times."
"You've kissed Jack?" the Oscar-winner asks excitedly. "Can I lick your face?"
"He played my father in a film called How Do You Know and the relationship that we had, that James L. Brooks, the director, wanted to portray was that of a very loving father and son," he said. "We would always kiss each other hello and goodbye. And James Brooks likes to film a scene 70 times...we just would always kiss."
"On the lips?" Mirren asks.
"M'hm, it was great," Rudd smiles before reenacting his very first kiss with Nicholson by grabbing Mirren and planting a giant smooch on her lips.
Check out the hilarious clip in its entirety below!
The Graham Norton Show bit airs on BBC America this Saturday, February 9 at 10:15 p.m. ET.