What would you do? Would you do this? 10 easy points?

Ok my guy cheated on me. He denies he had with them, yet I insisted he got tested for std's. He went to the emergency room to get the test done. Well I was going to buy a spoof card which changes the caller ID number and changes your voice. I was going to enter the doctors number as the one to show up on caller id and change my voice. I was going to say" this is Dr. ------ and your hiv test came back and it is positive we need to know how many partners you have had in the last year and some more information about your ual habits. Also we need to have the persons names and phone numbers so we can discreetly inform them" This way I would find out if he is having with other people and if he did if he used protection . Plus freak him out. Should I do it?