He flirts but I´ve heard he has a girlfriend?

I´ve known this guy for a month and a half and he has always given me the impression that he kind of liked me. However, even though he always seems very eager to talk to me, he hasn´t responded to my latest invitation to study together (or at least he said "great idea, I´ll let you know if I´ll be around school" but then didn´t follow up). His friend (whom I don´t think he sees much out of school though, so not sure how well they know each other) quickly mentioned he has a girlfriend, when referring to his summer plans he said "he has to do this thing with his girlfriend, or something". He said it vaguely, but pronounced the word "girlfriend".

Is there a higher chance that his friend is mistaken, or that I misunderstood all of his signals? How do I find out? I would feel so embarrassed now around him because I started to have a mini-crush on him, but now it turns out I´m a complete idiot! And I swear I would never have developed this mini-crush if it hand´t been for the way he looked at me.
He flirts but I´ve heard he has a girlfriend?
Post Opinion