I think its my fault 100 percent

Is it stupid if I got upset at my boyfriend for going to the movies with his guy and girl friends. But I haven't talked with him about why I'm upset as far as he knows I'm upset and I he has no idea why I was sort of yelling at him. What should I do? Should I be the first to apologize since I was the one who was really acting childish by not talking to him and just getting upset at him