Katherine Heigl and Gerard Butler premiered their romantic comedy 'The Ugly Truth' in Hollywood on Thursday night, and the stars revealed what truths they learned about dating, relationships, and the games that men and women play.

In the film, a morning show producer who is unlucky in love (Heigl), learns the ugly truth about what makes men and women tick from chauvinistic TV correspondent Mike Chadway (Butler).

Butler tells ET's Kevin Frazier what it was like to play such a bold and blunt character.

"They (women) never really find out what it is guys talk about, how it is guys view sex and relationships," he says. "That's what Mike Chadway, my character is all about, he's just going to lay out the ugly truth. I think deep down everybody knows to be honest. They know that there's a lot of that going on with guys. There's a lot of truth in that statement, and in fact they play it as well. They know when it's necessary to make themselves a little more sexy, how to get the upperhand, how to control. That's what's so great about the movie."

The actor may play a narrow-minded character in the film, but Heigl tells ET what her co-star was like on set when the cameras stopped rolling.

"It was pretty awesome," she says about working with Butler. "He's a great guy. He's got a lot of energy, and he's just got a really big heart. He's just super funny." 'The Ugly Truth' hits theaters July 24.

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