RappER. Technically, the person on the receiving end, would be the rappEE.

Same as employER, and employEE.

I think you're confusing rap with rape, and assuming a rapper is a rapist. Only one 'p' there.

joking lol i know its rapper but these things just run through my head

Lol I know, I just figured I'd get all technical and give a smart-ass response