Frazer Harrison/Getty ImagesKaty Perry will do anything for a good cause.
She'll even offer to have sex with you for the right price.
OK, maybe not, but last night at the American Foundation for AIDS Research (amfAR) "Inspiration Gala" in Los Angeles, she helped auction off a signed guitar by screaming out during the bidding, "I'll have sex with you, too."
Kidding aside, she did throw in another perk: taking the winning bidder to gay bar The Abbey.
Girls Gone Wild creator Joe Francis started things off with a $10,000 bid, but he was outdone by New York Giants owner Steve Tisch, who won with a $32,000 pledge.
Perry ran over to Tisch, hugged him and smiled, "I'm going to have sex with you."
Perry closed the event by performing five songs, including her hits "Wide Awake" and "Firework."
She also sang Bonnie Raitt's "I Can't Make You Love Me." No word if it had anything to do with men like Russell Brand or John Mayer, but she did say before belting out the tune, "This song needs no introduction."
The gala, held at Milk Studios and hosted by E!'s own Chelsea Handler, raised more than $1.3 million for the AIDS organization. Sarah Jessica Parker presented talent agent and CAA honcho Kevin Huvane with this year's Piaget Award of Inspiration.
Other celeb guests included Kate Hudson (she stunned in a body-hugging Prabal Gurung gown!), Octavia Spencer, Mark Salling, Kristin Davis, Jennifer Coolidge, 2 Broke Girls star Beth Behrs, Victoria's Secret model Alessandra Ambrosio and Rose McGowan.