"So, Cas, how about some ping pong?"
"I beg your pardon, Dean?"
"You know, ping pong, table tennis. That game where you hit a tiny ball back and forth over a table."
"I am not sure as to what you are referring." Castiel's face became the picture of ultimate confusion as he stared at Dean all the while not even blinking. At this point Sam glanced over from his laptop, chuckled, shook his head and resumed his fixation with the information on the current monster he was researching. Dean frowned a little and turned back to Castiel.
"Come on, Cas I'll show you. There's a table in one of the rec rooms."

For once the Winchester were staying at a hotel. Not a 5 star ultra-expensive one, just your average everyday hotel that had recreational facilities on top of the usual lodgings. Dean decided to take action and grabbed Castiel's sleeve, dragging him out of the room muttering a good-bye to Sam and shutting the door firmly in his wake.
"I do not understand, where are we going?"
"We're going to teach you ping pong, Cas." and with that the two stayed silent until they reached a room full of table-top football, billiards tables and, of course, ping pong tables.

Dean grabbed a couple of paddles and a ball left on the table by the previous users and threw one to Castiel who, naturally, caught it with great ease.
"So all you gotta do, Cas, is hit the ball back to me with the paddle, okay?" Castiel just nodded and copied Dean's stance as if it was necessary to play the game stood with your legs apart and slightly crouched. Dean bounced the ball on the table and served the ball to Castiel. Because of his strength, Castiel continued the rally right into Dean's face with great force. Dean dropped his paddle and his hand instantly flew to his right eye.
"Jesus, Cas, what did you do that for?"
"I apologise I did not realise that would happen." Castiel glided over to Dean and pulled his hand delicately from his injured eye. Castiel leaned forward, so close to Dean that Dean couldn't see him without growing cross-eyed, and placed a feather-light, chaste kiss onto Dean's eyelid. Dean instantly relaxed and let out a long sigh. He looked down into Castiel's beautiful blue eyes and his insides melted with the sheer concern and upset he saw in them.
"I can't stay mad at you, Cas."
"I know, Dean." he whispered as he wrapped his arms around Dean's waist, leaning into his body. Castiel closed his eyes and thought how this was his heaven. Dean wrapped one arm around Castiel's shoulders and left the other to softly stroke the dark, messy hair.

The pair decided to give up ping pong for a long while and instead spent their evening watching the stars and talking about nothing in particular.