READ DESCRIPTION! MY COUSIN NEEDS HELP WITH SOMETHING! INVOLVES PRANKING!?

Ok, so my cousin's ex-girlfriend Kelly broke up with him after dating and did the same for two of his friends. All three relationships lasted about one or two weeks. Now they all need a prank to pull on her for payback! Please no rude comments! (My cousin wanted to try the flaming bag of dog poo on her doorstep) PLEASE HELP ME!!!!!