Jessica Chastain reveals her grandma once left Bradley Cooper 'horrified' after sitting on his lap at a party when he had no idea who she was

• Jessica Chastain said that her grandmother once sat on Bradley Cooper's lap at a party.
• Chastain told Ellen DeGeneres that Cooper didn't know that the woman was her grandma.

Jessica Chastain recalled how her grandmother once sat on Bradley Cooper's lap at a party, saying that the actor "looked horrified" until Chastain clarified that the woman sitting on him was her grandma.

Appearing on Wednesday's episode of "The Ellen DeGeneres Show" to promote her new film "The 355," Chastain said that she had been trying to find her grandmother, Marilyn Herst, dates for "maybe 15 years, 20 years" by posting photos of her on dating sites like Match.com.

According to Chastain, her grandma has historically been excited to meet Chastain's costars. In the past, that's included actors like Al Pacino (who Chastain worked with on the 2013 film "Salomé") and Matthew McConaughey (who Chastain starred alongside in "Interstellar"), Chastain told DeGeneres.

Now, Herst is "at the age where she just really doesn't care," Chastain said, and she took things a step further when meeting Cooper at a house party that Chastain was hosting.

"In the middle of the party, she just walked over to Bradley and just like, sat on his lap," Chastain said. "He looked horrified, actually. He had never met her, he didn't know who she was, and I saw it kind of happening in slow motion where I was like 'Noooooo!'"

Chastain said that after she clarified that the woman was her grandmother, Cooper said, "Okay, okay, hi grandma!"

Chastain and her grandmother are famously close. Herst moved in with Chastain in April 2020, The Wall Street Journal reported. Chastain told WSJ that her grandmother "really runs into her life with open arms."