Sam and Dean went around the country and fought monsters, it's what they're good at, but they also got in way over their heads and Castiel knew that. But sometimes he just wished that he could step away from the war they fought and spend time alone with Dean. Ironic, what he was wishing for was freewill and that is what he fought for now in heaven. What kept him away from Dean.
Dean knew that Cas had to work in heaven, he knew about the war or thought he did. But that didn't stop him from missing Cas. He didn't think that it was asking much to see is face now and then to talk about each other maybe share a joke. Of course he never told Sam about any of this, he didn't need to have a chick moment with his overly-feely brother. Dean missed Cas.
Cas thought about how he missed Dean, a few minutes couldn't hurt right?! He dropped by while Sam was out to get coffee. "Hey Dean." He said and his own heart lightened in seeing Dean. "What did I say about sneaking up on me?" Dean said through a laugh, he missed Cas and had feelings that he couldn't explain, didn't understand.
Cas repressed the urge to hug Dean, he knew if he did then he wouldn't go back to the war he would want more, he would stay with Dean for as long as Dean wanted him there. And the world would be lost to Raphael.
When Cas left Dean's heart sunk. Why did he have to leave? Didn't he know that Dean loved him. That thought shocked Dean. Love? Did he really love Cas, the way he had loved Lisa? But he didn't have to ask himself, he knew when he thought the words that he did and the word love fit what he felt for Cas.
Cas was new at emotions, but when he was with Dean, he was happy and at peace, with Dean he was whole. But day after day he watched Dean go and spend the night with women, and he felt that Dean would never love him or atleast not in Jimmy Novak's body. He went to a hospital and found a woman who had recently joined heaven, " may i?" "yes," she replied, " for love" Cas slid into the beautiful woman's body and thought sadly how maybe Dean would love him now. Cas left and found Dean alone. He knocked on the door. Dean walked up to the door and let the woman in. Cas couldn't help it he ran into Dean's imbrace, Dean stumbled back in surprise but felt Cas inside the woman, he felt it in his heart, he held Cas in his arms and smiled, this was love.
Cas leaned up to kiss Dean, But Dean pulled away, Cas felt his heart crack, of course Dean didn't like him like this. " Dean" he said and was about to leave when Dean grabbed his wrist.
"If we do this, before this happens" Dean said holding Cas's face in his hands and rubbing Cas's jaw line with his thumb. " you need to know that I love you Castiel." He said, " I don't care what body you wear, I love you, no matter what vessel I love you." Dean grabbed Cas and their lips met. When they pulled away for air Cas was in Jimmy Novak's body again, and Dean kissed Cas again to prove his point. " I love you" they both whispered and Cas wrapped his wings around Dean as they kissed.
Cas and Dean could face the world together and their hands were never seen with out the others entwined fingers. They loved each other and that lasted for ever. Dean held Cas's hand in his and led him down the aisle. The church bells ringing behind them.