Oil up? Just open up. And say aahhh. "How do you get to Carnegie Hall?"
To the OP, anywhere on my Cock. Certainly. But I think there is something to say about contact on the taint and a tongue in the crack of my ass that kicks it up a notch.
The sweet spot is when that first explosion of "cum'" is going and the woman knows how to tighten her pussy to milk the rest of it out. Believe me that is a special and rare skill.