We are trying to finalize our guest list for our wedding. I am a martial artist and am in class with teens and adults. One of the teens in my class and I train and teach almost every day together and I have grown close to his parents as well. I want to invite him and his family but we are not inviting any children under 13 (unless they’re family). He has a younger brother who is 6 years younger than him. We adore but we don’t want anyone to get mad if we make an exception for him. Is it okay to not invite their younger brother?