I agree completely and that is a definition of UNITED. When a man and woman are UNITED in marriage, their MARRIAGE is a union, it DOES NOT mean that they are the same person.
Mat 19:5 And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh
This may have escaped your pope, being single and all, but there is a spiritual truth in two being united becoming one...