Has he just been leading me on or does he really like me?

Does he like me when he has a girlfriend?

Since the moment we met,we had an immediate connection.I know him so well and we have so many things in common.We can almost speak for each other when we’re in a group.He stares at me with a shine in his eyes and he is always smiling at me.We talk on the computer everyday, sometimes twice a day and sometimes one conversation can last for hours.We exchanged phone #’s and he’s invited me to his house a couple of times.I see him all the time and he always makes an effort to see me.The way he acts and talks to me,he makes it seem obvious that he likes me,but recently I found out that he has a girlfriend.Turns out a lot of people already knew and he’s been with her for a year.We have been soo close over the past year and not once did he mention or even give a bit of a clue to me that he was taken. I talk to him everyday and see him almost everyday,so where is she? And now he knows that I know about her.Does he really like me?Why has he hid her from me this whole time?