Fiancé included in sibling dinner or no?

So me and my siblings are having a sibling lunch, we all live in different areas and it’s kinda rare that we all get to spend some time together, maybe like once a month. My fiancé gets along well with my siblings, and hangs out with them as well when we are together. When I told him it was a sibling dinner he said okay have fun! I could tell he felt left out because he does spend time with them as well but he was trying to hide it. My fiancé and I normally have dinner together but I told my siblings if we are doing dinner my fiancé would probably be present and to be aware of that, my fiancé heard me say that to them as well. He excused himself when I said it was a sibling get together though.

Should fiancé be included in this kind of thing or not? I mean he would one day be their brother in law which is kinda a sibling but is it important to have JUST the siblings every now and then? He is respecting me either way I just didn’t know how to handle that kind of thing.