Fair warning, this is trivial 
Wedding invitation arrived for extended family wedding addressed to me and my sister. I haven’t lived with my sister for almost 14 years since we were teenagers. We aren’t close. I have no idea if she intends to go to this wedding. It appears however that we are a “duo” as far as this B&G are concerned. Niether of us have partners and I certainly wasn’t expecting a plus 1 but nor am I my sisters other half! It has made me feel like both a child and an old lady spinster who has lived with her sister all her life! 