Confused

So I’ve been talking to this guy for over a year...he’s a such an amazing guy! He’s the sweetest, he treats me right and I’m very happy. We text all the time, he came to visit me in my country and we had great sex. It’s a long distance thing. The only problem is he has never asked me to be his girlfriend but we act like we’re a couple. He introduced me to his best friend as his girlfriend. I’m just worry he hasn’t asked me out officially. I think it might destroy what we have if I ask him.