I had a sti, the guy is refusing to test

He was the only person i had sex with without a condom with since my last test in march. I have given and received head without a condom since him and the 2 people have both tested negative. He is the only person that has refused to get tested i dont know what to do And He blocked me tonight. I dont know what to do i dont want him to infect someone else if it was from him