So I had a masseuse in Toronto who explained that there was an extra $100 charge if I wanted anything more than a hand job at the end. And I said that the hand job was fine.
When he rolled me over on to my back and and saw my hard cock, he asked if he could climb on top because he got so turned on. I told him I wouldn't pay extra but that didn't stop him. He stayed rock hard as he rode my cock and even came when I pumped my load into him.
As someone on this thread mentioned, every situation is different.