Lawyers have the answers 1) we use the parties' names thus: "Charles (hereinafter called 'the husband')," or simply " Charles ( 'the husband')" and "Bill (hereinafter called 'the wife') or ('the wife') (2) we use A and B : "When a party A marries party B" or " A marries B" and (3) we remember the 1850 Interpretation Act, Lord Brougham's Act, which provides that the masculine shall import the feminine,or, as students remember the rule, the male shall embrace the female, so "he" is used for "he or she" unless the context otherwise requires.
Lord Brougham founded Cannes, which had been a fishing village until he was stopped there by a cordon sanitaire, liked it, built a house there and invited his friends down, who, in turn, built houses. Goodness knows what variations of couplings that all created.