It's like using the vessels of the Temple for profane winebibbing (didn't one of the pagan conquerors of Jerusalem do that?) or using the Ark of the Covenant for a cheese cupboard. Not that there's anything wrong with wine and cheese. But it's the desecration of something intimately consecrated to the Lord, for common use; which is to say, a sacrilege.
As I understand the bible, God looks pretty highly on marriage and all that it entails...He even likes babies...Lots of babies...
She married Joseph. The sacrament of marriage makes their procreation proper.
You degrade an act which is nigh unto holy in its proper context, demeaning her as little more than God’s whore for doing what God has ordained as righteous behavior between husband and wife.
The Levites ate of sacrificed meat and bread as their source of sustinence. Joseph, proper husband of Mary, was entirely right to partake of the wife which was sanctified as his.