I am posting from an alias to protect people's feelings from being hurt by asking advice here.
I am getting married August 25th and sending out the invites next month. Do I send my fiance's sister a +1 on her invite? I am not sure how to field this situation. She has a history of having turbulent unstable relationships. I just found out she is currently "dating" someone, but have no what his name is. She won't likely tell me his name if I ask either. She has a way of diverting questions she doesn't want to answer. Anyway, odds are she won't be with this guy by the wedding. No one on my guest list is getting a "+1". They will be invited with their SO if they have one. What's the best way to proceed with this?