Robert Irwin is stripping down & rocking tiny briefs in new underwear campaign

When he was approached for the campaign, Irwin tells People that "it was a pretty immediate yes." He also added that's he's "trying to do as many different and random exciting things" at this point of his career.

His sister Bindi Irwin, who's served a guest judge on Drag Race Down Under, was in attendance for the racy shoot and had no problem supporting her sexy brother.

"My family are so supportive, I just love them so much. They're the solid foundation to everything I do, and what we're doing together," Irwin says.

To see all of the racy photos, check out the exclusive full interview and spread on People's website here.