I ordered some yu-gi-oh cards online, resulting in a powerful Yu-gi-oh card deck, and duelled my friend with them. My friend, because I had such a good deck, lost. He then proceeded to sulk for the rest of the day, saying how he will sell his deck cheap on ebay. That day was ruined. He came the next day. Now I usually beat him because he isn't very good at the game, so he sulks for the rest of the day, but this time, he came the next day and continued to sulk, responding to a challenge by saying, "I would just lose anyway." He still didn't let it go!! I need help with this problem. I'm not the kind of person that just stops being his friend and finds some new ones. Also, my mother's strategies never work with him, and I am NOT a socialite. I really need help!