From WENN.com

The actor, who puckers up and smooches Michael Douglas in an upcoming Liberace biopic, admits he once asked Ledger how he prepared for intimate scenes with Jake Gyllenhaal in the 2005 drama.

Damon tells Playboy magazine, ""I remember asking Heath Ledger after Brokeback Mountain, 'How'd you do that scene with Jake?' - meaning the scene where they start ferociously kissing. He said, 'Well, mate, I drank a half case of beer in my trailer.'

""I started laughing and he goes, 'No, I'm serious. I needed to just go for it. If you can't do that, you're not making the movie.'""