I'd scream. Not of exitement, because I'm scared my house gets the Uglyness-Virus! Then I would kick his imagination-balls and THEN I call the cops and say that he attacked me and I just defended me. Then he gets arrested. Oh wait...Babys can't get arrested!!! Too bad... (my face would look a little like this XD)
The warrior in me would kick in (well...my warrior never actually leaves :D) and I would karate chop him in the throat and kick him in the teeth. The I would just plain scream in his face until he left.
After he left I would treat myself to a hot cocoa, even though it's August.
This would be my reaction. "GET THE HELL OUT OF MY HOUSE te CREEPER! JUST BECAUSE YOUR DUMB SONGS ARE PLAYED ON THE RADIO EVERY SO OFTEN DOESNT MEAN te CAN COME IN MY HOUSE! LEAVE o I'LL FILE A RESTRAINING ORDER!" Yup.
detto hi with a kind way... and when i shake his hand, i flip him over and then scream "HOW DARE te COME TO MY HOUSE!!!!!!!!!!!! te ARE NOT WELCOME HERE!!!!!! te EVEN NOT CLOSE TO BE A SINGER!!!!! AND IF te DARE TO SING AGAIN, te WILL END UP DEAD!!!" after that, i kick him in his you-know-what. :)