"Excuse you, Moony!" Sirius sounds offended and - in his opinion - very rightfully so. "I'm exactly the right kind of dramatic. Overdramatic. Pah. Who has ever heard such nonsense?"

That said he stalks ahead a few steps, dramatically, then slams open a door to an empty compartment, dramatically, and finally steps aside so he can gesture for Remus to go in first, dramatically. For added flair, he even bowed slightly. "Now go sit down and tell me everything about your summer, because any and all letters you sent were intercepted."