Q. Do I as a father usually does, also say the bracha of 'Baruch Sheptarani' (literally, blessed be the One who freed me from the punishment of this one), on Tisha Beav after my son gets his aliya, or should I wait until next day Monday?
A. See question above. Poskim also mostly maintain that this brocho is recited by the father when the son gets his aliya, as is done during other Bar Mitzvas. (See Poskim listed above).
Horav Shlomo Miller Shlit'a opinion is similar.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit'a