In beginning the planning for our wedding, my fiancee suggested using a Gospel which is not from the list of the 10 in the wedding section of the Lectionary. (We would like to use John’s crucifixion account).
She and I are both “hardcore Catholic” and want to do things correctly. Now the idea of using alternative readings is one I have heard of before and she has as well. In our understanding this was licit. That it is permitted is also asserted by reliable sources, such as Michelle Arnold here.
However, I cannot find anything in either the Rite of Marriage, the General Instruction for the Roman Missal, the Roman Missal itself, the Lectionary, or anywhere else which say that this is the case. The closest thing that I can find is this seemingly non-applicable clause from the GIRM #358 about weekday Mass readings:
“in Masses for special groups, the priest shall be allowed to choose texts more particularly suited to the particular celebration, provided they are taken from the texts of an approved Lectionary.”
GIRM #359, in reference to ritual Masses (and so the rite of Marriage celebrated during a Mass) states,
"In addition, in the Lectionary a special selection of texts from Sacred Scripture is given for ritual Masses into which certain Sacraments or Sacramentals are incorporated, or for Masses that are celebrated for certain needs.
Sets of readings of this kind have been so prescribed so that through a more apt hearing of the Word of god the faithful may be led to a fuller understanding of the mystery in which they are participating, and may be educated to a more ardent love of the Word of god.
Therefore, the texts proclaimed in the celebration are to be chosen keeping in mind both an appropriate pastoral reason and the options allowed in this matter."
It seems to me that the first two paragraphs of this suggest that no variation is possible, while the third suggests that it may be pursuant to some other rubric which I am unaware of.
If anyone has any helpful thoughts or is aware of some rubric or statement regarding this which I am not, it would be most appreciated!