In reply to:
Well, seems to me that the M3s are indeed small enough to fit into individual stockings hung by the chimney with care.
I wouldn't want to meet the woman that had stockings big enough for the M3s to fit!
As for the salutation, I use Happy Holidays... for the same reason I don't assume a man has a wife (and not a male partner) or that the white woman with the markedly oriental-looking child is the babysitter and not the child's mother (whether through adoption or interracial marriage).
If I know what the person celebrates, I'll call it by name - usually a "Merry" Christmas for the non-religious or C&E Catholics and a "Blessed" Christmas for the religious, even though I, myself, am not a religious man. My opinion is I'd rather make the other person feel good about the celebration, even if it requires a little more input than a knee-jerk "Merry Christmas" from me.
... also I try to keep my blaspheming to a minimum around the religious types... I shoot for no more than JC's name an an exclamation.
Bren R.