Sirius steps around the corner and levels his wand at Kingsley. Even though the tip of the wand is aiming between the small man's eyes, he grins impudently. "Prongs, Kingsley, and Padfoot had a pissing contest one night in an alley behind a pub in Leeds. Who won?"
He can't spare Remus a glance because he knows Remus will be dying of embarrassment. He can guess at what Kingsley's reaction will be. He's just happy to use a security question that isn't morbid, sad, or bloody.