beyond the shadow of a doubt...in the case of a Male/Female marriage it is nothing more than a fantasy to "Justify" the union as one where the couple's inability to procreate is just "INVOLUNTARY"...the proper word is "IMPOSSIBLE"...which puts that marriage on "EQUAL FOOTING" with a Same Sex marriage.
Again, if both marriages involve the "IMPOSSIBILITY" of procreation, why is one allowed and the other not?...there will NEVER be a child forthcoming from either...just a union of two LOVING persons to be celebrated.