Millie Bobby Brown said that unlike her 'Stranger Things' costars, Henry Cavill doesn't let her ask about his personal life

• Millie Bobby Brown said that Henry Cavill doesn't let her ask about his personal life.
• The pair play brother and sister duo Sherlock and Enola Holmes in "Enola Holmes."

Millie Bobby Brown said that her relationship with her "Enola Holmes 2" costar Henry Cavill is different from her "Stranger Things" castmates because she and Cavill have a "real adult relationship."

Speaking to Deadline about the upcoming film, which will be released on Netflix on Friday, Brown said that she and Cavill have boundaries in their relationship as costars. In the "Enola Holmes" films, they play brother and sister Sherlock and Enola Holmes.

"With Henry, it feels like a real adult relationship. Like a really good friendship a really healthy one. One that we have terms and conditions," Brown said. "I know Henry. He has terms and conditions with me. I'm not allowed to ask about his personal life. It's like, 'Millie, shut up. No.' And I'm like 'Understood.'"

In contrast, Brown said that her relationship with her costars on the Netflix series "Stranger Things" is more familial in nature, given that they grew up together. When the first season of the show premiered in 2016, Brown herself was 12 years old, with her young costars also in their preteens and early teens.

Brown and her costar Noah Schnapp, who plays Will Byers on "Stranger Things," previously said in an MTV News video published in June that they had a marriage pact that would go into effect if they were both still single when they turned 40 years old.

"With the 'Stranger Things' kids, it's different," Brown told Deadline. "There's no boundaries because it's like we're all siblings. But with Henry, he's very strict with me, which I appreciate."