He was definitely not expecting this or at least didn’t realise it will be so much more painful than he estimated. But once you’re tied down for your punishment, there’s not much else to do than focus on it, take it, and let its effects take place. I like to administer bastinado punishments because it’s quite rare for a slave to find any pleasure in it. Unlike caning his ass, and thighs or giving pain in other areas of the body, a quick, severe bastinado is pure punishment with no erotic element to it. Exactly what you need!