Funnyman Will Ferrell surprised Lakers fans -- not to mention friend John C. Reilly -- when he planted a kiss on his 'Step Brothers' co-star during last night's semi-final game against the Dallas Mavericks.

What prompted the man-on-man kiss? The Kiss Cam, of course.

Check out a larger photo of the lip-locked duo after the jump.

Noel Vasquez, Getty Images

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