why did he grape the twink after realizing he was putting so much pressure on him

why did he grape the twink after realizing he was putting so much pressure on him?? I can't understand his actions at all. when he realized he wasn't being good, he just graped him... like what was that for? to make the twink think he really is a piece of trash like all the loan sharks he had to deal with? to make him not attached emotinally..? help.. someone help me answer these questions