138. Unless otherwise expressly provided, nothing in this Act shall be construed as altering or amending the law in force on the coming into operation of this section relating to the capacity or consent required as respects a person in relation to any of the following:

(a) marriage;

(b) civil partnership;

(c) judicial separation, divorce or a non-judicial separation agreement;

(d) the dissolution of a civil partnership;

(e) the placing of a child for adoption;

(f) the making of an adoption order;

(g) guardianship;

(h) sexual relations;

(i) serving as a member of a jury.