Castiel stared at Dean lustfully, licking his lips and said, "ME GUSTA"
Dean walked towards Castiel, purposefully, and before claiming his lips in a searing kiss, he said it back.
ME GUSTA
Sam looked at the two, and whilst proud that they had finally admitted their feelings for each other (truthfully, they had gotten together a good 3 months ago, they wanted to see how long they could keep a secret), wished they would keep it in private. Then Gabriel popped in, grabbed Sam, and popped out again, reappearing in a motel room. The two couples had great times, well separated, each with a human in love with an angel and an angel in love with a hunter.
What happened that night exactly is up to you.
2 years later
Castiel and Dean made their way up to Sam and Gabriel's house, looking forward to seeing their niece and nephew. Gabriel's first-born (his daughter) was a full-fledged angel to be with beautiful golden-green wings (2 sets, 4 total wings), whilst his son was a human boy that Sam was happily raising to want to be a lawyer. Castiel was now 4 months pregnant with Dean's baby. Sam and Gabriel were very proud of their twins, and Cas was looking forward to the triplets that he was carrying. He hadn't told any of them quite yet, but knew that Dean would be as excited as he was. Once inside, and seated around the living room, with the munchkins playing in their playpen, Castiel announced his amazing news, and because he was waiting to see Dean's gleeful reaction, was able to watch first-hand as his husband of a year fainted.
3 years later
Castiel, Dean and their 3 daughters (2 humans and an angel (with a set of bright blue wings, with a spattering of deep green feathers), all of whom were overly spoiled, but still knew to keep the secret) met with Gabriel and Sam and their now 5 children (2 sets of twins, the original one of each, another set of twins with 2 boys, one of whom was another angel with 2 sets of beautiful hazel colored wings, and the other was another human (Sam was hoping this one might want to be a doctor, using his little bit of grace to help heal people), and the single child born, another little angel girl with 3 sets (6 total wings, the first born arch-angel) of bright white wings), all of whom knew to keep the angels secret), prepared to walk in a pride parade. Castiel was pregnant with twins, but was luckily only 3 months pregnant (angel pregnancies are faster than humans, he looks about 4/5 months pregnant), and thus able to hide it for the most part. Gay and Lesbian marriages had just been declared federally legal, making their marriages legal in every American State, and they were celebrating.
15 years later
Sam cried as the first couple of his children left for college, he knew in his heart that with one of them being an angel they would be home often, but he was still proud, and looking forward to hearing all about it. All of his children had decided to get a human education, and the angels among them were planning to stay in the human world at least for a good number of years. These kids were learning to be lawyers, following in their father's planned steps for his grown-up life. The next set were planning to be doctors (just like he had planned for them) and the last one was thinking to learn to become a teacher, even if she never actually became a teacher. No one in heaven knew of the arch-angel born to one of the few arch-angels still alive, and Gabriel (and Castiel) planned to keep it that way. Especially since there weren't many angels that even knew that Gabriel was alive.
Castiel was surrounded by his children, all of whom wanted to know when their dad was going to be home. Cas wasn't sure himself, so they were all just sort of sitting around in the front room, longing and hoping that Dean would be home soon. He had gone out for a quick, and easy hunt in the area, there hadn't been indication of anything bad happening, so they were all wondering what was taking so long. Finally Cas stood up and indicated that the children should go do their homework. So the kids scattered, hoping to be done soon so they could be there to greet their father when he finally arrived home. Once all of the children (the twins ended up being 2 boys, one human who loved guns at least as much as his father did, but also enjoyed nature and bees as much as his daddy, and an angel with deep green wings with bright blue feathers along the outer edge (one set) who was the exact opposite of his brother, loving bees and nature, and having basically respect for weapons) were out of the room, Castiel opened up his bond with Dean (gained when they married, and bonded as soul mates as the angels do), and sent out a probe, wondering what was happening. He got back a feeling of warmth and a sense of being home soon. So Cas sat back, and continued to wait. Half an hour later, and the last child returned to the front room, as Dean walked in the door. He held up little nick-nacks for everyone, most were bee-themed, or some sort of honey themed, but a couple were more gun or hunting themed. Castiel's was the most elaborate, being a crystal honey bee on top of a comb of honey. He apologized but said that he had ordered the crystal bee weeks ago, and it was finishing up when he showed up, so he had had to wait to bring it home.
Sam and Gabriel were content with their life, and lived for quite a few more years, before Sam realized he hadn't aged in years, and that was when they realized that the angel bonding had had a side effect. Sam was an angel of Castiel's caliber, brought there by his mate being an arch-angel. Sam's wings were a lighter version of Gabriel's wings, and Gabriel thought that as time went on and as they strengthened their bond, that Sam might be elevated to be his equal.
Castiel and Dean were more than content with their life, and after their children left the house, they went back to traveling, though they still met with the kids often, and maintained the house. But they enjoyed the world, and realized a good amount of time before Sam that Dean had been elevated to angel status, their love having been absolute, and their bond having been established such a long time before their marriage, that Dean was easily made Castiel's equal. Dean's wings were the same color as his eyes, making his wings a little lighter in some areas than his sons, and a bit darker in others.