How to address wedding invite for adult siblings living together

View Quoted Comment In so many situations I feel like people would be more likely to roll their eyes at you sending 5 invitations to the same address, than to mind about having one joint invitation...

Seriously this is never something I even would have thought twice about until this site 😂 why would you send two of the same thing to the same house?

Older etiquette books cite both traditions: Children of the household over 18, who may or may not have SO invited, get their own invitations, sent wherever they are at the time invites go out, at college, own apt. or home. But in the case of older siblings, or parent and child, or cousins who have lived in the same household for years, with no SO in the picture, they may be treated as a social unit if they customarily are each others' companions at social events, and you would not think of inviting one without the other. So by their long term though not romantic companionship, they may be on one invitation as a social unit. With grown kids, you may invite some you k ow, and not others you are not close to. And some with SO, and so.e not. So if over 18, or under but ha e moved out of the family house, they do not go on parents. And do not have to be invited, even if their parents, and 3 younger brothers and sisters are.

I looked up the above in 4 traditional etiquette books before my wedding, because of people's comments. Then FI has several pairs of elder widows or widowers who live together with a sibling or cousin, have for years and years, and I have two pair like that. Truly their own social unit, as much as any romantic couple living together.

I personally am doing two invites. One would say
”Mr. So and so and guest” if they are getting invited with a guest and the other would say
“Ms. So and so and guest”