Half an hour with someone new, otherwise an hour. Would consider longer with a good regular if I had the budget.
Of course she'd like to spend some of that time chatting, but I don't mind that if she does it on my terms: in cowgirl or lying on top of me, with me giving her a slow comfortable screw while she prattles away.
I think that's a very civilised way to hold a conversation, I just wish it was more socially accepted. I could stroll up to a pretty girl at a social event, guide her gently to a sofa, then drop my trousers and sit down: "nice dress you're wearing, would you mind hitching it up and climbing aboard? Thank you. So, tell me about yourself, do you come here often?"