Falling in love is not against UK law, but the act of intimacy with a child under the age of 16 is.  All the adult person has to do is wait until the child is of age of consent before any acts of love take place.  If the love between the two is strong, then the bond will last , if at the age of consent the love is not there then this is what the law is there for, to protect the child and also the adult.