The True Blood star, who plays a stripper in the film alongside Channing Tatum and Matthew McConaughey, admitted that the unconventional costume took time to get used to while shooting.
"I wore these little thongs that literally go up your butt, and it definitely takes getting used to," Manganiello told People.
"It was uncomfortable at first. It sort of felt like a wedgie, but once you get into the routine of wearing one, you know what to do and you just do your thing. We all had to suffer a bit for our craft."
He went on to insist that he had no problems wearing such revealing items in front of his co-stars, adding: "We all took our turn in the barrel. Being with the guys, nobody takes themselves too seriously. Everybody was on set cheering, laughing and rolling on the ground."
Magic Mike is opening in cinemas on June 29 in the US and July 13 in the UK. The film is partly based on Channing Tatum's real-life experiences as a teenage stripper.
Watch Channing Tatum chat to Digital Spy about Magic Mike below: