Islam is about rules -do and do nots It is a way of life. Here no matter how many times you call some one a "SON" or a girl a "Daughter".No matter even if the whole of your country calls him "SON"-The fact is He is not Your "SON",because relationships do not sprout in imagination,it is created by blood.And Islam put this imagination and man made relationships to an end.And there is nothing wrong in Prophet's marriage.