Actor Viggo Mortensen, who is straight, has defended his decision to play a gay role in his directorial film debut.

The Falling premieres Monday in Britain.

In the film, Mortensen, who is best known for his roles in the Lord of the Rings trilogy and Green Book, plays a man whose father is suffering from dementia. The racist and homophobic father comes to live with his son and husband, who is Chinese-Hawaiian, in Los Angeles.

Activists have criticized straight, cisgender actors who play LGBT characters. Halle Berry recently pulled out of a transgender film role over backlash that a transgender person should be offered the role.

“I apologize to all the proctologists for casting David Cronenberg,” Mortensen joked, referring to Cronenberg playing a colorectal surgeon in the film.

“There are certain characters I'm not going to play. I wouldn't play Eric, the Chinese-Hawaiian American,” Mortensen, who is Danish-American, told Reuters.

Mortensen, who also wrote and directed the film, said that the decision to make his character gay was not “a gimmick, anchor, or some trigger.”

“There's been so much injustice toward under-represented groups, racially, sexual orientation [and in terms of] sexual identity,” he said.