Morning Suit Equivalent

[ggibby]

I, for one, would advise against wearing the kilt to a wedding in France as it would certainly up-stage the bride ...
... Mr. and Mrs. X are the ones to be consulted if one wishes to dress in something other than the requested attire, not the bride.

Exactly. Not his wedding, not his party, and since it's been specified, not his choice of attire.