Is there a way to tell if a guy is interested in you from his text messages?

The guy in question is incredibly intelligent, borderline socially awkward, but the funniest person I've ever met. He texts me all of the time telling me random stories, inside jokes, funny things that happened etc. We see each other every day and text on average probably 5-6 days a week. He's always the one who texts me first and lately he's been using my name in the texts. I don't know if this is significant or not but I've heard that if someone of the opposite uses your name frequently, they're interested in you. (That might not be true but whatever) The only thing is whenever we're alone or with a group he's fine but whenever he's around his best friend "Cara", he acts very standoff-ish and barely speaks to me. I know for a fact he definately doesn't have a romantic interest in her, and she and I get along great so she doesn't have a problem with me but for some reason he's more stingy towards me when she's there. So can someone enlightenment me? What is his deal? I would greatly appreciate some input!