Carolyn Hax: Is it ‘selfish’ to skip holiday gatherings with sister’s in

Dear Carolyn: We are a very small family — just me, my older sister and my parents. Five years ago, my sister married into a very large family, and her in-laws host all the holidays. We’re always invited, but it’s never any fun for us. There are 20 of them together, talking and laughing, and me and my parents in the corner by ourselves.