a) procreation is not (as you claimed) the reason most people marrry
b) straight married couples have **families** comprised of step-children (one person's bio kid), adopted kids, bio kids from previous relationships, surrogacy, IVF, etc. So those straight couples didnt BOTH create those kids.
c) having kids is not a requirement for marriage, period, so why are you demanding it be one for gays?
Have I covered it all?