instead of lawsuits or brute force, why don't you ask him "Are you a fag (gay) ? Because you seems very interested in my sexuality. FYI I'm not gay, so i don't like you, i like girls, do you have any sister ? " Be prepared that he might get angered about the last question
Or you can take the scientific approach using the numbers and articles that others users replied above.
Or you can also ignore him, make him see that his words don't get to you, and that you are bigger than him. He's trying to get you annoyed, and if you keep feeding that, you'll continue annoying you. Ignore him. Sometimes the biggest victory is achieved when you walk away. Good Luck