So between FI and I we have 4-5 nieces/nephews/cousins who are 18 (thus they get their own invite) but they are still in high school. So what is the etiquette on plus 1s? Do they get a plus 1? Are we required to invite boyfriends or girlfriends? I realize they are considered adults but they are also still in high scool. And some of them will be traveling with their families. Thoughts??