Matthew McConaughey will soon be seen on the big screen in one of the darkest roles of his career, playing Killer Joe Cooper in the NC-17 film, "Killer Joe."

Although the NC-17 ruling may seem harsh, the 42-year-old star said the rare rating is deserved.

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"I don't know if I agree with why they gave it a NC-17 ruling, but for the reasons they say they gave it a NC-17 rating -- we're NC-17 with a capital 'N', a capital 'C' and a big '1' and '7'," Matthew told Access Hollywood in a new interview on Wednesday.

"Killer Joe" is definitely loaded with sex and violence, but Matthew said it's also funny -- filled with blasphemous humor.

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"When I first read the script, I didn't like it! I thought I got it and what I thought I got, I was disgusted by," he told Access. "I remember I said, 'I want to take a hot shower with a steel brush.' So I said, 'Alright, give me a few days and let me shake this first experience of this first read and go back and read it.'

"I did, and I found myself chuckling at a few things at first, then I found myself laughing hard, then I found myself having belly laughs," he added.

While Matthew is playing a contract killer in the crime thriller, off screen, the actor is a bona fide family man, having just married the mother of his two (and soon-to-be three!) children, Camila Alves.

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"Life is really good right now," he said. "I'm happily married, I'm happy we have another healthy child, so far, in Camila's belly."

"Killer Joe" - which also stars Emile Hirsch, Juno Temple and Gina Gershon -- hits select theaters on July 27.

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