DREIST ! bare fucked by best friend

That can't be true? What kind of action was that... My best mate wants to sleep at my place because he's been kicked out. Well, that was nothing new for me. This time, however, he apparently hadn't had sex for a while, because as soon as I wanted to sleep, the bed somehow started to shake. I turn round and .... Is he crazy? I didn't know what to say. I was really perplexed and somehow horny at the same time - such an old bastard! I would never have thought that of him! What should I do .... ?