How do I get my freind off of Wow?

I went over to my freind's house a few months ago to ask him if he wanted to go catch a movie. When I arrived, I noticed he was playing world of warcraft. I got excited because I have been trying to get him to play with me for months. I went over and helped hm creat his character, level up, ect. About a week later I came back over to check on him because he didn't come to work for two days in a row. When I got there he was playing WoW. I asked him if he had been playing it while he should of been at work, and he replied "I was suppost to go to work today?". I kinda got mad because I umed that he skiped coming to my football game to play Wow. I just left. A few days later, I saw his girl freind at the market. She said that he had texted he stated that he was sick. I was tempted to tell her the truth, but I didn't because I didn't want to cause problems. Over the past month he has pasted up going outside, going to my house, and even from his GF. And when he does show up for work he is all grumpy. Me other freinds say he'll grow out of it, but I'm concered that he wont.