All human relationships are temporary, even as we ourselves are temporary. There is probably an unwritten rule preventing clerics from mentioning this during marriage ceremonies. To them befalls, “What God has joined together…”
The more fearful a man is, the more identified he is with his body. As he sees himself, so he sees everyone else. Often, he fixates on certain parts of the body. It happens that body parts meet, marry and say: “You complete me.” This is partly true.