Kingsley had nothing but praise for the billionaire twin.
"There is a very passionate scene in the film which we filmed last week. It went extremely well and she was very focused. She was very good, very professional," Kingsley told Access Hollywood in an interview airing Wednesday night. "She was quite wonderful."
Although the actor realizes there might be some controversy over the 40-year age difference between the on-screen smoochers, he says it's much ado about nothing.
"She is this great free spirit, you know, she is equally seducing, so it is a level playing field," Kingsley said. "[It's] for a few seconds and then we disappear and we never see each other in the movie. But she is a trigger into my quest for happiness."
"I would say the two of them, Josh and Mary-Kate, are great role models for their contemporaries," he said. There are so many kids at their age tragically crashing and burning, and not these two. They are so hard-working, so focused and so good to be with. They are wonderful people to be with."
The film, currently in production, also stars Famke Janssen, Olivia Thirlby and Method Man.
Olsen is also a guest star on Season 3 of the off-beat Showtime comedy "Weeds," which premiered this week.