Hello! FI and I have a mutual friend who we would like to invite to the wedding. FI's parents are good friends with his parents, so they are on FMIL's list. Our friend has a younger brother (19 years old) who we do not know very well. Is it rude to not include him, and only send an invitation to our friend, and then a seperate one to his parents? In other cases, we are not inviting any kids of people on our parent's list...only the couples. This one just feels different because we would only be excluding one member of the family. Thanks in advance!