step on someone's toes

step on someone's toes (third-person singular simple present steps on someone's toes, present participle stepping on someone's toes, simple past and past participle stepped on someone's toes)

1. (idiomatic) To cause someone offense, especially by trying to control something that is under their authority, or interfering in their private affairs.

   I didn't think I'd be stepping on my sister's toes when I told my nephew to sit up straight at the dinner table.