Matthew Mitchum Auctions His Funky Trunks

Olympic gold medalist Matthew Mitcham gave the crowd a surprise treat this past weekend when he hosted the Closing Gala of the Melbourne Cabaret Festival: As reported by Same Same, the Aussie diver stripped off his suit and auctioned off his Funky Trunks undies!

How much would you have bid?

Matthew became a brand ambassador for Australian swimwear and underwear line Funky Trunks in 2010. "There isn't another suit I've seen that reflects my colorful disposition quite like them," the out athlete told The Advocate of the partnership.

For $1,000, which benefitted Australian Marriage Equality, Adam Lowe took home the Funky Trunks right off Matthew's bum -- plus a signed copy of the athlete's book, Twists and Turns.

Mitcham also opened the evening with a ukulele performance and later performed a strip version of Aqua's "Barbie Girl" accompanied by harpist Tara Minton.

Find more photos from the event at Same Same and see more photos of Matthew modeling Funky Trunks underwear here.