Stanley Tucci naturally has a host of famous friends, but many were surprised to discover that his family also boasts some well-known names.

Regal Union Square had unexpected visitors on Tuesday (23 September) when Tucci and John Krasinski attended a film screening. The stars of The Hunger Games and The Office were seen with popcorn and drinks before settling in to watch One Battle After Another, featuring Leonardo DiCaprio.

The New York cinema shared on Instagram: "You never know who might stop by Union Square! Thanks for joining us @johnkrasinski and @stanleytucci."

However, on Reddit, users were astonished to learn that Tucci and Krasinski share more than a friendship; they are actually related.

Stanley Tucci and John Krasinski were spotted together at Regal Union Square cinema recently (Instagram/@regalunionsquare)

A post described them as 'brothers-in-law', which prompted social media users to question their family connections.

One user inquired: "What is the connection here? Is Stanley Emily's brother? Or did he marry John's sister?"

Numerous commenters clarified the situation, noting that Tucci and Krasinski are married to Felicity and Emily Blunt, respectively, who are sisters.

Emily Blunt starred alongside Tucci in the memorable 2006 film, The Devil Wears Prada, where they became friends.

The Oppenheimer actor eventually met Krasinski in 2008 at a restaurant, introduced by a mutual friend.

Upon meeting Blunt, the A Quiet Place actor admitted he was 'so nervous', telling Ellen DeGeneres on her show in 2011: "I was like, 'Oh god, I think I'm going to fall in love with her.' It's one of those moments where you just know."

The couple married in 2010, and Tucci attended the wedding ceremony, where he met Blunt's sister, Felicity, although they had previously met at the premiere of The Devil Wears Prada.

Tucci (far right) is married to Felicity Blunt (far left), who is the sister of Emily Blunt (second left), and is married to John (second left) (Sylvain Gaboury/Patrick McMullan via Getty Images)

At that time, the Big Night star was married to his first wife, Kate, who also attended the premiere. He told Marc Maron in 2021 that the two women had a conversation that night, adding: "I have a picture of them together, which is quite unusual."

Kate passed away in 2009 due to breast cancer.

After reconnecting with Felicity at Emily and John's wedding, they soon began dating.

The couple eventually married in 2012 and have two children together, a son and a daughter. Tucci also has three children, two daughters and a son, from his marriage to Kate.

The actor and the literary agent have a 21-year age difference, which was a challenge for Tucci early in their relationship.

He told BBC Radio 4's Desert Island Discs in 2023: "I was afraid to enter a relationship, and I kept trying to end it.

"I'm 21 years older than she is, and I didn't want to feel old for the rest of my life! But I realized she was an incredibly special person."

Nonetheless, the Blunt family warmly welcomed the Lovely Bones star into their family, with Emily telling PEOPLE in 2022: "He's a true Renaissance man who knows how to win everyone's hearts. And it's through having a genuinely good time.

"He's incredibly intelligent, quick to laugh, enjoys being laughed at, charismatic, warm, and full of energy."