How do you reject an MC?

Okay - for people that don't know, I'm looking for an MC. Some guy asked for horrorcore beats, and I was intrigued considering I hadn't done shit like that. So I made beats like that, and asked the guy to record something for me to listen to how he sounds. Unfortunately, it was garbage. He was a 17 year old, white (polish, italian, austrian) kid in danbury, connecticut. He had an extremely monotonous flow. He never varied his pitch, he never stressed words. And he said some garbage about death and Christ and stuff like that (and quoted Star Trek - wtf?). So basically, he sucked. I'm now going to attempt to tell him that I won't give him any beats, but I don't want to just straight up tell the guy "you suck, never talk to me again". I figured I could mysteriously disconnect and block him on the AIM. But he has my slsk ID and my e-mail (of course I could block him there also). It's a lot like breaking up with someone in the sense that you don't want to "hurt" them, but at the same time, you gotta get out of the situation. Wish me luck.