Rub In Meaning

(transitive, idiomatic) To irritatingly make a point.

Example: 2006 July 19, “On The Fridge”, Washington Post:
  Flattening chicken breast halves serves two purposes: It provides more surface area to rub in the Greek-influenced seasoning, and it ensures that the chicken cooks quickly.
2003 March 9, Glenn Davis, “U.S. vs. Mexico a day of celebration, opportunity”, Houston Chronicle:
  Postcards from Florida might mean someone is rubbing in the fact he or she has been lounging on the white, sandy beaches