Blake Lively’s sister, Robyn Lively, has been married to High School Musical star Bart since 1999.
Chris got married to Arnold’s daughter Katherine Schwarzenegger in 2019, and they’ve since welcomed three kids together.
Jack got married to Margaret Qualley in 2023, making her mom, Andie MacDowell, his mother-in-law.
Emily and Stanley, who famously starred in The Devil Wears Prada together, have been related by marriage since 2012, when he married her sister, Felicity Blunt.
Cameron is married to Good Charlotte member Benji Madden. Benji's twin brother, Joel Madden, is married to Nicole — and she and Cameron are super, super close.
Josh's dad, James Brolin, has been married to Barbra since 1998.
Peter has been married to Jake’s sister, Maggie Gyllenhaal, since 2009.
Michelle got married to Phoebe's younger brother, Jasper Waller-Bridge, back in 2023.
Mark has been married to Meryl’s daughter Grace Gummer since 2021.
And finally, Penn is married to Girls star Jemima’s sister Domino Kirke, with whom he welcomed twins earlier this year.