Mark Ruffalo – star of the gay parenting flick The Kids Are Alright – has slammed gay marriage opponents as “bigoted.”

In an interview with Fox News' entertainment blog Pop Tarts, the 42-year-old actor said he disagreed with opponents of gay marriage.

“It's the last dying, kicking, screaming, caged animal response to a world that is changing, a world that's leaving a lot of those old, bigoted, un-accepting views behind. It's over,” Ruffalo said.

In The Kids Are Alright, Ruffalo plays Paul, the biological father of two children being raised by a lesbian couple. The film stars Academy Award nominees Julianne Moore and Annette Bening as the couple whose family dynamic is altered in unexpected ways when their children seek out Paul.

Kids got a buzzy premiere in January at the Sundance Film Festival, where it was acquired by Focus Features, and went on to win the Teddy Bear at the 60th Berlin International Film Festival.

Ruffalo also said gay families are no different than heterosexual families.

“We live down the street from a gay couple with a young son, my son goes and plays there and has lunch there. My son is 8 years old, and not once has he come and asked why his friend has two poppas,” he said. “His family is no different to my family – they eat at the same time, send their kid to school, discipline him and love him the same way. It's only the teaching that we give to the child that makes them see those distinctions.”

The Kids Are Alright opens Friday in select cities.