Child's Play

I tiptoed down the stairs, moving swiftly into the kitchen, out of sight but peeking around the corner to witness this amazing turn of events. Two boys, heads close together, searching through a bin of toys and making a plan.
"I know, you be Darth Vader and I'll be Harry Potter and pretend you are trying to kill me and I put a spell on you" says the older boy.
"Wel-l-l-l okay" says the younger brother as they move quickly to set up their scene. Light sabre versus wand action commenced, Darth Vader was quickly defeated and the boys moved onto a new plan of action.

I waited for it, the sharp exclamation "HEY!" followed by smacking noises, crying and outright rage. It didn't happen. I waited for the "That's not fair - M-O-O-MMMMMMMMM!" and the ensuing mad race to get up the stairs (where they think I am) to get to me first to tell on the other. It didn't happen. Was it possible that they were actually playing? Did I just hear J make a suggestion for their play and C actually said "okay" instead of overriding him, or worse, yet, hauling off and smacking his brother.

Who are these boys and can I keep them?