"Come on, Cas!" Dean whined, pulling Castiel by the arm into the new arcade that was recently built. "Even angels have to have fun sometimes."
Cas's face was one of complete patience – Dean knew he didn't want to be wasting time playing arcade games when he could be fighting angel wars and what not; but he also knew that Cas wouldn't want to let Dean down by leaving him.
"I don't think I quite get the human word of 'fun', Dean." He replied, while he continued to be led around.
Dean stopped him in front of a kissing machine and grinned. "That's because you don't hang out with me enough."
"Dean-"
"Shut up, Cas, I'm trying to teach you how to laugh more." That silenced Castiel from complaining any more, and he watched as Dean started motioning to the kissing machine like a kid would have done with his mother if he saw a balloon man. "This is one of my favorites. I played it all the time as a kid to try and impress some chick... usually just ended up disgusting them..." Dean's eyes seamed to glaze over as he recalled memories of former girlfriends, and Castiel waited patiently for him to return to real life. "But anyhow! I want you to test it out." Dean's childish grin returned, making Castiel smile. He always enjoyed when Dean was happy, because so often was he not.
"What do I do?" Castiel looked at the machine in utter confusion – human pleasures were so complicated.
Dean casually wrapped his arms around Castiel, making him blush. Dean took Cas's hands in his and started breathing in his ear. "Well, the kissing machine is supposed to tell you how good of a kisser you are. Depending on how hard you squeeze this lever," he pointed to the lever of the machine, "You'll either be a horrible kisser, a passionate kisser, or... a naughty kisser!"
Castiel's blush rose to new levels at the thought of him being a... naughty kisser. "Dean, I'm not so sure this is a good idea."
"Nonsense, Cas. You're not going to have a bad time on my watch. Come on... please... for me."
There he went, pulling that 'for me' card again. Like usual of course; but Castiel couldn't say no when Dean asked him for something. He cared to much for him.
"Alright. Just this once." And with Dean's arms around him, Cas squeezed the lever as hard as he could, and got... horrible. His cheeks turned beat red, his eyes looking immediately down, as Dean started laughing so hard that tears were running down his face,
"Ah, Cas, you make my day!" He continued chuckling, putting a smile on the angel's face. "Here, let me try." Castiel stepped out of Dean's way, to let him expertly pull on the lever. And what Dean got really didn't surprise Cas. "Booyah! Naughty kisser!" Dean threw his arms up in the air, his mouth open like a 5 year old who won some candy, while he celebrated his 'winning'. Then he saw Castiel's face, and his look of shame.
"Cas, come on now. You haven't been with anyone – it's to be expected." He tilted Castiel's face up, letting the angel look into his eyes. "You have beautiful blue eyes; I don't see how you could be single with eyes like these."
Castiel bit his lip, blushing. "Dean-"
But Dean interrupted him again. "Shh. I'll make you get up to a naughty kisser in no time, angel. Just don't tell Sam about this."
And with that, he claimed Cas's lips with his, training him in the art of kissing, and more importantly – love.