I wish I could tell you (especially since you are requesting this information with such a noble goal in mind) but the ultimate swear word is known only to the rich, powerful, and famous.
Your best bet will be to run away from your parents’ home, join the circus, and work your way through the rank until you become the headliner (perhaps as a strongman, or bearded lady, or dancing walrus — do you have a walrus costume?). Hopefully you will be spotted by a talent scout. All the best talent scouts look for fresh blood in travelling circuses.
From there, you will become famous enough to learn the word, and finally get back at your parents.
Also you’ll be rich enough to train a lion to eat them. Which is awesome.
