When you are using couples initials in the form of S&J, whose initials go first, the girl or guy's?
Who ever wears the pants!!! So in your case it would be the lady's!!! Lol!!! Just kidding!!!
Usually the guy's, but it doesn't matter.
I would think you could go with alphabetically.
Use Ladies first and you will never be wrong.
A gentleman,always has the lady go first.
Girls.. I've seen it that way on soooo many save the dates and wedding invites