Russell Brand Cheats on Katy Perry -- With Jason Segel!

Credit: Noel Vasquez/

Katy Perry sings about kissing girls -- and her fiance Russell Brand likes making out with boys.

Brand, 34, laid a smooch on How I Met Your Mother star Jason Segel, 30, during the Stand With Haiti benefit concert in Los Angeles Tuesday night.

See more star PDA!

Brand also got a bit cheeky; he grabbed his Forgetting Sarah Marshall costar’s booty on stage.

Jack Black's band Tenacious D headlined the concert, which also featured performances by The Shins and Aimee Mann.

They're not the only ones getting in on the act.

The night before, Nicole Richie, Usher, Pink and others came together to re-record "We Are the World" to fundraise for earthquake relief.

Check out photos of all the stars who were there!

The original Michael Jackson tune was released in 1985 to raise funds for Live Aid.