The upcoming film Dirty Grandpa will show Aubrey Plaza and Robert De Niro getting up close and personal. On a visit to Jimmy Kimmel Live! Plaza gives detail on how the filming really went down.

“We’re soulmates,”; Plaza, 31, jokes. “Robert De Niro’s character lies and says he’s a professor and my character has this obsession with having sex with a professor so I kind of zero in on him.”;

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Recalling a certain sex scene with De Niro, 73, Plaza says it took “a solid nine, maybe ten”; hours to complete.

“There was a lot of interesting stuff that went down, you know,”; she sys. “We didn’t totally plan out the scene, so we didn’t really know what was going to go down.”;

The Parks and Recreation star explains how she was urged to try different things, but some things worked while others not so much.

“I’d try to get in there and suck on his nipples, and he was like batting me away, and I didn’t know if it was in character or not,”; she says. “And then they’d cut the camera and [the director] called me back and was like “Bob does not like his nipple area paid attention to.”;

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Watch the full interview below and catch Dirty Grandpa in theatres January 22.