Well, what did you expect him to say? You said this wasn't something you'd ever done before, so he was responding to the history you have. (This doesn't mean he wasn't flattered or aroused... he was just surprised.)
Maybe next time you should send him a script?
BTW - I don't see what's so wonderful about being aroused without an appropriate release in sight. To me, that is just frustrating. My filthy imagination works pretty well on its own.
Relax... I'll need some information first. Just the basic facts - can you show me where it hurts?