A guy I like doesn't want a relationship, but he treats me like his girlfriend. What to do?

I meet his friends and his family. He kisses me holds my hand and proudly introduces me to anyone he knows. He says he doesn't want the commitment because he is too busy with other things in his life. Should I continue with things the way they are? Or should I tell him that we can only be buddies. I'm confused on why he won't call me his girlfriend.