The first time he tried on the barely-there underwear, Bomer, 34, "put it on wrong and my junk didn't fit in it," he recently told MTV News. "I had to call a wardrobe person and go, 'Something's wrong with my thong, you guys. I think we're gonna have to figure this out.'"
The risque costumes helped Bomer bond with his A-list costars Channing Tatum, 31, Alex Pettyfer, 21, Joe Manganiello, 34, and Matthew McConaughey, 41.
"There hasn't really been a movie like this before, and we did it all on a g-string budget," he added. "So I'm excited to see what people think."