Geez, Jonah! Oscar nominee Jonah Hill shared a TMI story involving Joe Pesci on Late Night With Jimmy Fallon Thursday, Jan. 23. 

"I love Joe Pesci. I mean who doesn't? He's the best," Hill, 30, said of the 70-year-old Oscar winner. "Goodfellas is my favorite film of all time and his performance is my favorite."

Hill encountered Pesci for only the second time ever at the recent premiere of Wolf of Wall Street as he paid his respects to the film's also-legendary director, Martin Scorsese, who told him, "'Ey, Kid! Come here…this is Joe!'" The 22 Jump Street actor continued, "Just standing there with Scorsese and Joe Pesci - the three of us in a conversation. I was just like, 'What the hell am I doing here, you know?'"

Once Scorsese moved on, the conversation became unexpectedly intimate between Hill and Pesci. "He goes, 'You're great in the movie, kid, I'm really proud of you.' And I'm like, 'Thank you, your acting means so much to me,'" Hill recalled of his convo with Pesci. "And he goes, 'Here's what I want you to do: I want you to go buy a helmet.' And I go, 'okay…'"

"He goes, 'I want you to keep the helmet next to your bed and then every night, I want you to go in the bathroom and put the helmet on -- every night,'" Pesci said to the young actor. "And if ever the helmet doesn't fit, it's because too many people are going up here.' And he puts his fingers in my ass!" Hill motioned as Fallon bursted out into laughter.

While the audience went wild, the camera panned over to Roots drummer Questlove, whose jaw dropped in response.

"[Joe] was dying laughing and I was dying laughing and he's like 'Good job, kid' and he like left," Hill added.

The awkward encounter, however, left Hill even more awestruck by Pesci: "I was like, 'You're the coolest person I've met in my entire life!'" he gushed. "He's just a man's man."