Exactly! As far as I know there is this duality / union of the oposites thing, hence why there are so many androginy in entertaiment industry these days... But when you get married it is a union of feminine and masculine, living in harmony...
I'm not going trough the spiritual aspects of marriage now, but there is a general aspect regarding this, specially in catholicism at least. And then there are kids, who are at least supossed to be the expected result of this dualistic union.
The Gnostics version say as spirits we embody both but once down the tree of life we're bound to one gender. They pursue androgyny to ascend to higher sepiroth? Whereas Christian perspective is God wants us to realise our nature as masculine or feminine and unify through matrimony. I am however new to all this and learning as I go!
The alchemical marriage or chemical romance is embodied by Baphemot. It is not connected to the roots of Christianity. Are there elements present in the Vatican? Of course, nothing but Pharisees in the RCC leadership.