Okay, this may be a dumb question but it's really been confusing me. So I'm at the age where most of my friend's don't have children, so I was thinking about asking my fiancé to ask his sister to let his niece and nephew to be the flower girl and ring bearer at our wedding. But if I do this, do we need to include his sister and her husband in our wedding party? I wasn't planning on having my own brother and sister in the wedding party because it's really not their thing, but I don't know how'd they'd feel if my future in-laws were in it. Also, my fiancé was his brother-in-law's best man, but since then he and his family had a falling out and are just now reconnecting. So I don't know them like, at all (have only met once in the past 4 years) and don't know if they'd expect to be included or not. What should I do?