Alcoholic

So my husband has always been against drinking. When we first got together I said I was fine with drinking on special occasions. He was against that. Now that he has turned 21 he is steadily drinking every one of his off days of work. I told him he was becoming an alcoholic and I will not tolerate it. He swears he is not an alcoholic but to me he is. He drinks at least 3 beers till he is tipsy or drunk every night he is off. Remind you he is only 120 pounds so it doesn't take much to get him drunk. So is it just me or is he really becoming an alcoholic?