(Cover) - EN Showbiz - Bradley Cooper says Ed Helms' reaction was funnier than the full frontal nudity itself in The Hangover Part II.

The Hollywood actor stars in the sequel to the hugely-popular comedy film which follows a group of friends who head to Thailand after the bachelor party in Las Vegas for Stu's wedding.

Bradley, who plays Phil in the movie, says despite his co-stars being fully naked in the film, he was more amused by Ed Helms' reaction. The American star has revealed that Ed, who plays Stu in the movie, responded in a far funnier way than actually shooting and seeing his co-stars naked.

"I was more shocked by watching Ed's reaction to it all and how amazing it was. Just watching Stu having to find out what went down," he said in an interview with Entertainment Tonight.

The 36-year-old actor says not much "craziness" happened off set. He insists that all the bad behaviour was captured on screen.

"Much like the first one, all the craziness you see is in the film. There's not much you could try to outdo once the shooting day is over. My favourite thing to do was putting my headphones on and walking round the city," he confessed.

Ed believes Bangkok was the perfect place to raise the bar for the film's comedic value. The actor says the cast and crew were automatically convinced as soon as the city was mentioned.

"The whole thing about doing a sequel was can we up the ante enough to make it worthwhile', and Bangkok was an automatic yes! That sounds like a good way to raise the stakes," he revealed.

The 37-year-old star became ill whilst shooting. He says the pain was unbearable, and combined with having to shoot strenuous scenes, he really struggled.

"What's the sickest you've ever felt from food poisoning? And then multiply that by 10,000. And then have to shoot a riot scene," he said. (C) Cover Media