A stone falling into a pool. At first, there is the splash of ecstasy; of water meeting stone; of softness meeting hardness; of two elements, fundamentally different, coming together and making one. This is the glorious passion of the first few meetings where you meet and become one.
Then the ripples start growing larger as you gently meet others in your circles. Your kids, your parents and your close friends meet the other and you see your lover reflected in their eyes, and their worlds. Slowly you learn more, both about your lover and your friends and family as the ripples grow larger.
Then you become an acknowledged couple. The ripples have fused and you are recognised as being together in the larger circles. You meet people together, entertain together, even, perhaps at this stage become engaged, living together, married. Still fundamentally different, one a hard stone, one yielding water, you become a third entity, together ready to rest together, always.
Finally, the ripples reach the end of the pond. The degree of depth changes and become shallower. You find those ripples further away from that initial passion, that beginning splash that combined you together. Either you both move together into a further dimension and become part of the main fabric of society, happy and co-joined, stone and water, or else, lose that essential connection to that first splash and divide once more into separate elements. Of course, even if you divide, you are changed. Even if one of you is still a stone, and one of you is still water, your essential matter has experienced that immutability of stone and the freedom of water. You move on to seek a different pool, another body of water, to make your own.