I never laid a hand on him....
 
Some suggested grettings:
"You didn't have to go through all this just for a box of chocolates... get well!"
"WTF?!  ANOTHER BIRTHDAY?!!"
" I can't believe you actually graduated!!"
" Happy Fathers Day!" ( this one come complete with a long to-do list)
 
Or, of course, you can request your own custom greeting!