If your sister-in-law is the wife of your brother, she is the mother of your brother's son. Her son-in-law would then be the brother-in-law of your brother's son.If your sister-in-law is your...
No, your son-in-law is married to your daughter and his brother is not your son-in-law, but simply your son-in-law's brother or your daughter's brother-in-law.
Your son-in-law is the husband of your daughter. His son is your daughter's son and therefore your grandson, and you are his grandparent. If your son-in-law's son is from a previous marriage, the son...