Just imagine Cas and Dean are both small kids, three or four years old. They live in the same neighborhood, their parents are very good friends and two boys were born in the same year. And then in one day when the weather was nice and warm, both families, the Novak and the Winchesters, decided to go out for a picnic on the shore of the river. After a few hours of relaxation when their parents were slightly tipsy, Cas and Dean decided to play on the sand a few feet away from their parents. During their innocent game, Dean suddenly approached Cas and hugged him as sincerely as only little kids can hug and said loudly, "Mom, Dad, when Cas grows up, he will be my husband."
Parents, naturally, burst out laughing: little kids rarely understand what they are saying. But Dean knew exactly what he said and 20 years later happy Dean and Cas stood before the altar and spoke their loving vows to each other.
